diff --git a/mod/bookmarklet.php b/mod/bookmarklet.php
index 1c4d191c4..f15d12d6d 100644
--- a/mod/bookmarklet.php
+++ b/mod/bookmarklet.php
@@ -29,7 +29,7 @@ function bookmarklet_content(App $a)
 
 	if (!strstr($referer, $page)) {
 		if (empty($_REQUEST["url"])) {
-			System::httpExit(400, ["title" => L10n::t('Bad Request')]);
+			throw new \Friendica\Network\HTTPException\BadRequestException(L10n::t('This page is missing a url parameter.'));
 		}
 
 		$content = add_page_info($_REQUEST["url"]);
diff --git a/mod/cal.php b/mod/cal.php
index 5baffec8a..ce6d501ff 100644
--- a/mod/cal.php
+++ b/mod/cal.php
@@ -31,11 +31,11 @@ function cal_init(App $a)
 	}
 
 	if (Config::get('system', 'block_public') && !local_user() && !remote_user()) {
-		System::httpExit(403, ['title' => L10n::t('Access denied.')]);
+		throw new \Friendica\Network\HTTPException\ForbiddenException(L10n::t('Access denied.'));
 	}
 
 	if ($a->argc < 2) {
-		System::httpExit(403, ['title' => L10n::t('Access denied.')]);
+		throw new \Friendica\Network\HTTPException\ForbiddenException(L10n::t('Access denied.'));
 	}
 
 	Nav::setSelected('events');
@@ -43,7 +43,7 @@ function cal_init(App $a)
 	$nick = $a->argv[1];
 	$user = DBA::selectFirst('user', [], ['nickname' => $nick, 'blocked' => false]);
 	if (!DBA::isResult($user)) {
-		System::httpExit(404, ['title' => L10n::t('Page not found.')]);
+		throw new \Slim\Exception\NotFoundException();
 	}
 
 	$a->data['user'] = $user;
diff --git a/mod/dfrn_notify.php b/mod/dfrn_notify.php
index 745411a8e..1a9f98fa3 100644
--- a/mod/dfrn_notify.php
+++ b/mod/dfrn_notify.php
@@ -29,7 +29,7 @@ function dfrn_notify_post(App $a) {
 
 			$user = DBA::selectFirst('user', [], ['nickname' => $nick, 'account_expired' => false, 'account_removed' => false]);
 			if (!DBA::isResult($user)) {
-				System::httpExit(500);
+				throw new \Friendica\Network\HTTPException\InternalServerErrorException();
 			}
 			dfrn_dispatch_private($user, $postdata);
 		} elseif (!dfrn_dispatch_public($postdata)) {
diff --git a/mod/dfrn_poll.php b/mod/dfrn_poll.php
index 5b72c0bf9..6c849cb80 100644
--- a/mod/dfrn_poll.php
+++ b/mod/dfrn_poll.php
@@ -50,7 +50,7 @@ function dfrn_poll_init(App $a)
 
 	if (($dfrn_id === '') && empty($_POST['dfrn_id'])) {
 		if (Config::get('system', 'block_public') && !local_user() && !remote_user()) {
-			System::httpExit(403);
+			throw new \Friendica\Network\HTTPException\ForbiddenException();
 		}
 
 		$user = '';
@@ -59,7 +59,7 @@ function dfrn_poll_init(App $a)
 				DBA::escape($a->argv[1])
 			);
 			if (!$r) {
-				System::httpExit(404);
+				throw new \Friendica\Network\HTTPException\NotFoundException();
 			}
 
 			$hidewall = ($r[0]['hidewall'] && !local_user());
@@ -483,7 +483,7 @@ function dfrn_poll_content(App $a)
 			// heluecht: I don't know why we don't fail immediately when the user or contact hadn't been found.
 			// Since it doesn't make sense to continue from this point on, we now fail here. This should be safe.
 			if (!DBA::isResult($r)) {
-				System::httpExit(404, ["title" => L10n::t('Page not found.')]);
+				throw new \Friendica\Network\HTTPException\NotFoundException();
 			}
 
 			// URL reply
diff --git a/mod/display.php b/mod/display.php
index acc2a5b09..fa5b2e196 100644
--- a/mod/display.php
+++ b/mod/display.php
@@ -20,6 +20,7 @@ use Friendica\Model\Group;
 use Friendica\Model\Item;
 use Friendica\Model\Profile;
 use Friendica\Module\Objects;
+use Friendica\Network\HTTPException;
 use Friendica\Protocol\ActivityPub;
 use Friendica\Protocol\DFRN;
 use Friendica\Util\Strings;
@@ -76,7 +77,7 @@ function display_init(App $a)
 	}
 
 	if (!DBA::isResult($item)) {
-		System::httpExit(404);
+		return;
 	}
 
 	if ($a->argc >= 3 && $nick == 'feed-item') {
@@ -200,8 +201,7 @@ function display_fetchauthor($a, $item)
 function display_content(App $a, $update = false, $update_uid = 0)
 {
 	if (Config::get('system','block_public') && !local_user() && !remote_user()) {
-		notice(L10n::t('Public access denied.') . EOL);
-		return;
+		throw new HTTPException\ForbiddenException(L10n::t('Public access denied.'));
 	}
 
 	$o = '';
@@ -254,7 +254,7 @@ function display_content(App $a, $update = false, $update_uid = 0)
 	}
 
 	if (!$item_id) {
-		System::httpExit(404);
+		throw new HTTPException\NotFoundException(L10n::t('The requested item doesn\'t exist or has been deleted.'));
 	}
 
 	// We are displaying an "alternate" link if that post was public. See issue 2864
@@ -303,8 +303,7 @@ function display_content(App $a, $update = false, $update_uid = 0)
 	$is_owner = (local_user() && (in_array($a->profile['profile_uid'], [local_user(), 0])) ? true : false);
 
 	if (!empty($a->profile['hidewall']) && !$is_owner && !$is_remote_contact) {
-		notice(L10n::t('Access to this profile has been restricted.') . EOL);
-		return;
+		throw new HTTPException\ForbiddenException(L10n::t('Access to this profile has been restricted.'));
 	}
 
 	// We need the editor here to be able to reshare an item.
@@ -340,7 +339,7 @@ function display_content(App $a, $update = false, $update_uid = 0)
 	$item = Item::selectFirstForUser(local_user(), $fields, $condition);
 
 	if (!DBA::isResult($item)) {
-		System::httpExit(404);
+		throw new HTTPException\NotFoundException(L10n::t('The requested item doesn\'t exist or has been deleted.'));
 	}
 
 	$item['uri'] = $item['parent-uri'];
@@ -415,7 +414,7 @@ function displayShowFeed($item_id, $conversation)
 {
 	$xml = DFRN::itemFeed($item_id, $conversation);
 	if ($xml == '') {
-		System::httpExit(500);
+		throw new HTTPException\InternalServerErrorException(L10n::t('The feed for this item is unavailable.'));
 	}
 	header("Content-type: application/atom+xml");
 	echo $xml;
diff --git a/mod/fetch.php b/mod/fetch.php
index 3e9c4e662..492f319ef 100644
--- a/mod/fetch.php
+++ b/mod/fetch.php
@@ -14,9 +14,8 @@ use Friendica\Database\DBA;
 
 function fetch_init(App $a)
 {
-
 	if (($a->argc != 3) || (!in_array($a->argv[1], ["post", "status_message", "reshare"]))) {
-		System::httpExit(404);
+		throw new \Friendica\Network\HTTPException\NotFoundException();
 	}
 
 	$guid = $a->argv[2];
@@ -42,13 +41,13 @@ function fetch_init(App $a)
 			}
 		}
 
-		System::httpExit(404);
+		throw new \Friendica\Network\HTTPException\NotFoundException();
 	}
 
 	// Fetch some data from the author (We could combine both queries - but I think this is more readable)
 	$user = User::getOwnerDataById($item["uid"]);
 	if (!$user) {
-		System::httpExit(404);
+		throw new \Friendica\Network\HTTPException\NotFoundException();
 	}
 
 	$status = Diaspora::buildStatus($item, $user);
diff --git a/mod/follow.php b/mod/follow.php
index ba4ff35f1..e0b6e1733 100644
--- a/mod/follow.php
+++ b/mod/follow.php
@@ -17,7 +17,7 @@ use Friendica\Util\Strings;
 function follow_post(App $a)
 {
 	if (!local_user()) {
-		System::httpExit(403, ['title' => L10n::t('Access denied.')]);
+		throw new \Friendica\Network\HTTPException\ForbiddenException(L10n::t('Access denied.'));
 	}
 
 	if (isset($_REQUEST['cancel'])) {
diff --git a/mod/hcard.php b/mod/hcard.php
index e27ea29be..828eeaf09 100644
--- a/mod/hcard.php
+++ b/mod/hcard.php
@@ -17,8 +17,7 @@ function hcard_init(App $a)
 	if ($a->argc > 1) {
 		$which = $a->argv[1];
 	} else {
-		notice(L10n::t('No profile') . EOL);
-		return;
+		throw new \Friendica\Network\HTTPException\NotFoundException(L10n::t('No profile'));
 	}
 
 	$profile = 0;
diff --git a/mod/help.php b/mod/help.php
index cdfedac6f..19b629271 100644
--- a/mod/help.php
+++ b/mod/help.php
@@ -62,11 +62,7 @@ function help_content(App $a)
 	}
 
 	if (!strlen($text)) {
-		header($_SERVER["SERVER_PROTOCOL"] . ' 404 ' . L10n::t('Not Found'));
-		$tpl = Renderer::getMarkupTemplate("404.tpl");
-		return Renderer::replaceMacros($tpl, [
-			'$message' => L10n::t('Page not found.')
-		]);
+		throw new \Friendica\Network\HTTPException\NotFoundException();
 	}
 
 	$html = Markdown::convert($text, false);
diff --git a/mod/hovercard.php b/mod/hovercard.php
index 603c617ca..ca3991963 100644
--- a/mod/hovercard.php
+++ b/mod/hovercard.php
@@ -31,7 +31,7 @@ function hovercard_content()
 
 	// Get out if the system doesn't have public access allowed
 	if (intval(Config::get('system', 'block_public'))) {
-		System::httpExit(401);
+		throw new \Friendica\Network\HTTPException\ForbiddenException();
 	}
 
 	// Return the raw content of the template. We use this to make templates usable for js functions.
diff --git a/mod/notice.php b/mod/notice.php
index edcbefdad..b0a6a5439 100644
--- a/mod/notice.php
+++ b/mod/notice.php
@@ -16,7 +16,7 @@ function notice_init(App $a)
 		$nick = $r[0]['nickname'];
 		$a->internalRedirect('display/' . $nick . '/' . $id);
 	} else {
-		notice(L10n::t('Item not found.') . EOL);
+		throw new \Friendica\Network\HTTPException\NotFoundException(L10n::t('Item not found.'));
 	}
 
 	return;
diff --git a/mod/poco.php b/mod/poco.php
index 064e0e9a8..c288f6b63 100644
--- a/mod/poco.php
+++ b/mod/poco.php
@@ -22,7 +22,7 @@ function poco_init(App $a) {
 	$system_mode = false;
 
 	if (intval(Config::get('system', 'block_public')) || (Config::get('system', 'block_local_dir'))) {
-		System::httpExit(401);
+		throw new \Friendica\Network\HTTPException\ForbiddenException();
 	}
 
 	if ($a->argc > 1) {
@@ -31,7 +31,7 @@ function poco_init(App $a) {
 	if (empty($nickname)) {
 		$c = q("SELECT * FROM `pconfig` WHERE `cat` = 'system' AND `k` = 'suggestme' AND `v` = 1");
 		if (!DBA::isResult($c)) {
-			System::httpExit(401);
+			throw new \Friendica\Network\HTTPException\ForbiddenException();
 		}
 		$system_mode = true;
 	}
@@ -73,7 +73,7 @@ function poco_init(App $a) {
 			DBA::escape($nickname)
 		);
 		if (! DBA::isResult($users) || $users[0]['hidewall'] || $users[0]['hide-friends']) {
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		$user = $users[0];
@@ -371,8 +371,9 @@ function poco_init(App $a) {
 			$ret['entry'][] = [];
 		}
 	} else {
-		System::httpExit(500);
+		throw new \Friendica\Network\HTTPException\InternalServerErrorException();
 	}
+
 	Logger::log("End of poco", Logger::DEBUG);
 
 	if ($format === 'xml') {
@@ -385,6 +386,6 @@ function poco_init(App $a) {
 		echo json_encode($ret);
 		exit();
 	} else {
-		System::httpExit(500);
+		throw new \Friendica\Network\HTTPException\InternalServerErrorException();
 	}
 }
diff --git a/mod/probe.php b/mod/probe.php
index e120ce172..7fc3a9289 100644
--- a/mod/probe.php
+++ b/mod/probe.php
@@ -10,9 +10,9 @@ use Friendica\Network\Probe;
 function probe_content(App $a)
 {
 	if (!local_user()) {
-		System::httpExit(403, ["title" => L10n::t("Public access denied."),
-			"description" => L10n::t("Only logged in users are permitted to perform a probing.")]);
-		exit();
+		$e = new \Friendica\Network\HTTPException\ForbiddenException(L10n::t("Only logged in users are permitted to perform a probing."));
+		$e->httpdesc = L10n::t("Public access denied.");
+		throw $e;
 	}
 
 	$o = '<div class="generic-page-wrapper">';
diff --git a/mod/pubsub.php b/mod/pubsub.php
index c5744f399..e5ede6c80 100644
--- a/mod/pubsub.php
+++ b/mod/pubsub.php
@@ -12,10 +12,9 @@ use Friendica\Core\System;
 function hub_return($valid, $body)
 {
 	if ($valid) {
-		header($_SERVER["SERVER_PROTOCOL"] . ' 200 OK');
 		echo $body;
 	} else {
-		System::httpExit(404);
+		throw new \Friendica\Network\HTTPException\NotFoundException();
 	}
 	exit();
 }
@@ -24,7 +23,7 @@ function hub_return($valid, $body)
 
 function hub_post_return()
 {
-	System::httpExit(200);
+	throw new \Friendica\Network\HTTPException\OKException();
 }
 
 function pubsub_init(App $a)
diff --git a/mod/pubsubhubbub.php b/mod/pubsubhubbub.php
index 342facd10..f71984ec1 100644
--- a/mod/pubsubhubbub.php
+++ b/mod/pubsubhubbub.php
@@ -17,7 +17,7 @@ function pubsubhubbub_init(App $a) {
 	// PuSH subscription must be considered "public" so just block it
 	// if public access isn't enabled.
 	if (Config::get('system', 'block_public')) {
-		System::httpExit(403);
+		throw new \Friendica\Network\HTTPException\ForbiddenException();
 	}
 
 	// Subscription request from subscriber
@@ -44,7 +44,7 @@ function pubsubhubbub_init(App $a) {
 			$subscribe = 0;
 		} else {
 			Logger::log("Invalid hub_mode=$hub_mode, ignoring.");
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		Logger::log("$hub_mode request from " . $_SERVER['REMOTE_ADDR']);
@@ -61,7 +61,7 @@ function pubsubhubbub_init(App $a) {
 
 		if (!$nick) {
 			Logger::log('Bad hub_topic=$hub_topic, ignoring.');
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		// fetch user from database given the nickname
@@ -69,13 +69,13 @@ function pubsubhubbub_init(App $a) {
 		$owner = DBA::selectFirst('user', ['uid', 'hidewall', 'nickname'], $condition);
 		if (!DBA::isResult($owner)) {
 			Logger::log('Local account not found: ' . $nick . ' - topic: ' . $hub_topic . ' - callback: ' . $hub_callback);
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		// abort if user's wall is supposed to be private
 		if ($owner['hidewall']) {
 			Logger::log('Local user ' . $nick . 'has chosen to hide wall, ignoring.');
-			System::httpExit(403);
+			throw new \Friendica\Network\HTTPException\ForbiddenException();
 		}
 
 		// get corresponding row from contact table
@@ -84,7 +84,7 @@ function pubsubhubbub_init(App $a) {
 		$contact = DBA::selectFirst('contact', ['poll'], $condition);
 		if (!DBA::isResult($contact)) {
 			Logger::log('Self contact for user ' . $owner['uid'] . ' not found.');
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		// sanity check that topic URLs are the same
@@ -93,7 +93,7 @@ function pubsubhubbub_init(App $a) {
 
 		if (!Strings::compareLink($hub_topic, $contact['poll']) && !Strings::compareLink($hub_topic2, $contact['poll']) && !Strings::compareLink($hub_topic, $self)) {
 			Logger::log('Hub topic ' . $hub_topic . ' != ' . $contact['poll']);
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		// do subscriber verification according to the PuSH protocol
@@ -121,19 +121,19 @@ function pubsubhubbub_init(App $a) {
 		// give up if the HTTP return code wasn't a success (2xx)
 		if ($ret < 200 || $ret > 299) {
 			Logger::log("Subscriber verification for $hub_topic at $hub_callback returned $ret, ignoring.");
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		// check that the correct hub_challenge code was echoed back
 		if (trim($body) !== $hub_challenge) {
 			Logger::log("Subscriber did not echo back hub.challenge, ignoring.");
 			Logger::log("\"$hub_challenge\" != \"".trim($body)."\"");
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		PushSubscriber::renew($owner['uid'], $nick, $subscribe, $hub_callback, $hub_topic, $hub_secret);
 
-		System::httpExit(202);
+		throw new \Friendica\Network\HTTPException\AcceptedException();
 	}
 	exit();
 }
diff --git a/mod/receive.php b/mod/receive.php
index b0258acbd..db1287ea6 100644
--- a/mod/receive.php
+++ b/mod/receive.php
@@ -22,7 +22,7 @@ function receive_post(App $a)
 	$enabled = intval(Config::get('system', 'diaspora_enabled'));
 	if (!$enabled) {
 		Logger::log('mod-diaspora: disabled');
-		System::httpExit(500);
+		throw new \Friendica\Network\HTTPException\InternalServerErrorException();
 	}
 
 	if (($a->argc == 2) && ($a->argv[1] === 'public')) {
@@ -32,13 +32,13 @@ function receive_post(App $a)
 		$public = false;
 
 		if ($a->argc != 3 || $a->argv[1] !== 'users') {
-			System::httpExit(500);
+			throw new \Friendica\Network\HTTPException\InternalServerErrorException();
 		}
 		$guid = $a->argv[2];
 
 		$importer = DBA::selectFirst('user', [], ['guid' => $guid, 'account_expired' => false, 'account_removed' => false]);
 		if (!DBA::isResult($importer)) {
-			System::httpExit(500);
+			throw new \Friendica\Network\HTTPException\InternalServerErrorException();
 		}
 	}
 
@@ -49,7 +49,7 @@ function receive_post(App $a)
 	if (empty($_POST['xml'])) {
 		$postdata = file_get_contents("php://input");
 		if ($postdata == '') {
-			System::httpExit(500);
+			throw new \Friendica\Network\HTTPException\InternalServerErrorException();
 		}
 
 		Logger::log('mod-diaspora: message is in the new format', Logger::DEBUG);
@@ -71,7 +71,7 @@ function receive_post(App $a)
 	Logger::log('mod-diaspora: decoded msg: ' . print_r($msg, true), Logger::DATA);
 
 	if (!is_array($msg)) {
-		System::httpExit(500);
+		throw new \Friendica\Network\HTTPException\InternalServerErrorException();
 	}
 
 	Logger::log('mod-diaspora: dispatching', Logger::DEBUG);
@@ -83,6 +83,9 @@ function receive_post(App $a)
 		$ret = Diaspora::dispatch($importer, $msg);
 	}
 
-	System::httpExit(($ret) ? 200 : 500);
-	// NOTREACHED
+	if ($ret) {
+		throw new \Friendica\Network\HTTPException\OKException();
+	} else {
+		throw new \Friendica\Network\HTTPException\InternalServerErrorException();
+	}
 }
diff --git a/mod/salmon.php b/mod/salmon.php
index 84d2942d5..ba1bc8d46 100644
--- a/mod/salmon.php
+++ b/mod/salmon.php
@@ -28,7 +28,7 @@ function salmon_post(App $a, $xml = '') {
 		DBA::escape($nick)
 	);
 	if (! DBA::isResult($r)) {
-		System::httpExit(500);
+		throw new \Friendica\Network\HTTPException\InternalServerErrorException();
 	}
 
 	$importer = $r[0];
@@ -49,7 +49,7 @@ function salmon_post(App $a, $xml = '') {
 
 	if (empty($base)) {
 		Logger::log('unable to locate salmon data in xml ');
-		System::httpExit(400);
+		throw new \Friendica\Network\HTTPException\BadRequestException();
 	}
 
 	// Stash the signature away for now. We have to find their key or it won't be good for anything.
@@ -87,7 +87,7 @@ function salmon_post(App $a, $xml = '') {
 
 	if(! $author_link) {
 		Logger::log('Could not retrieve author URI.');
-		System::httpExit(400);
+		throw new \Friendica\Network\HTTPException\BadRequestException();
 	}
 
 	// Once we have the author URI, go to the web and try to find their public key
@@ -98,7 +98,7 @@ function salmon_post(App $a, $xml = '') {
 
 	if(! $key) {
 		Logger::log('Could not retrieve author key.');
-		System::httpExit(400);
+		throw new \Friendica\Network\HTTPException\BadRequestException();
 	}
 
 	$key_info = explode('.',$key);
@@ -130,7 +130,7 @@ function salmon_post(App $a, $xml = '') {
 
 	if (! $verify) {
 		Logger::log('Message did not verify. Discarding.');
-		System::httpExit(400);
+		throw new \Friendica\Network\HTTPException\BadRequestException();
 	}
 
 	Logger::log('Message verified with mode '.$mode);
@@ -177,8 +177,7 @@ function salmon_post(App $a, $xml = '') {
 	//if((DBA::isResult($r)) && (($r[0]['readonly']) || ($r[0]['rel'] == Contact::FOLLOWER) || ($r[0]['blocked']))) {
 	if (DBA::isResult($r) && $r[0]['blocked']) {
 		Logger::log('Ignoring this author.');
-		System::httpExit(202);
-		// NOTREACHED
+		throw new \Friendica\Network\HTTPException\AcceptedException();
 	}
 
 	// Placeholder for hub discovery.
@@ -188,5 +187,5 @@ function salmon_post(App $a, $xml = '') {
 
 	OStatus::import($data, $importer, $contact_rec, $hub);
 
-	System::httpExit(200);
+	throw new \Friendica\Network\HTTPException\OKException();
 }
diff --git a/mod/search.php b/mod/search.php
index 9a70bcac9..1416f1d89 100644
--- a/mod/search.php
+++ b/mod/search.php
@@ -98,12 +98,9 @@ function search_content(App $a) {
 	}
 
 	if (Config::get('system','local_search') && !local_user() && !remote_user()) {
-		System::httpExit(403,
-				["title" => L10n::t("Public access denied."),
-					"description" => L10n::t("Only logged in users are permitted to perform a search.")]);
-		exit();
-		//notice(L10n::t('Public access denied.').EOL);
-		//return;
+		$e = new \Friendica\Network\HTTPException\ForbiddenException(L10n::t("Only logged in users are permitted to perform a search."));
+		$e->httpdesc = L10n::t("Public access denied.");
+		throw $e;
 	}
 
 	if (Config::get('system','permit_crawling') && !local_user() && !remote_user()) {
@@ -123,10 +120,7 @@ function search_content(App $a) {
 		if (!is_null($result)) {
 			$resultdata = json_decode($result);
 			if (($resultdata->time > (time() - $crawl_permit_period)) && ($resultdata->accesses > $free_crawls)) {
-				System::httpExit(429,
-						["title" => L10n::t("Too Many Requests"),
-							"description" => L10n::t("Only one search per minute is permitted for not logged in users.")]);
-				exit();
+				throw new \Friendica\Network\HTTPException\TooManyRequestsException(L10n::t("Only one search per minute is permitted for not logged in users."));
 			}
 			Cache::set("remote_search:".$remote, json_encode(["time" => time(), "accesses" => $resultdata->accesses + 1]), Cache::HOUR);
 		} else
diff --git a/mod/viewcontacts.php b/mod/viewcontacts.php
index 7c2b96fad..14919820d 100644
--- a/mod/viewcontacts.php
+++ b/mod/viewcontacts.php
@@ -20,18 +20,18 @@ use Friendica\Util\Proxy as ProxyUtils;
 function viewcontacts_init(App $a)
 {
 	if (Config::get('system', 'block_public') && !local_user() && !remote_user()) {
-		System::httpExit(403, ["title" => L10n::t('Access denied.')]);
+		throw new \Friendica\Network\HTTPException\ForbiddenException(L10n::t('Access denied.'));
 	}
 
 	if ($a->argc < 2) {
-		System::httpExit(403, ["title" => L10n::t('Access denied.')]);
+		throw new \Friendica\Network\HTTPException\ForbiddenException(L10n::t('Access denied.'));
 	}
 
 	Nav::setSelected('home');
 
 	$user = DBA::selectFirst('user', [], ['nickname' => $a->argv[1], 'blocked' => false]);
 	if (!DBA::isResult($user)) {
-		System::httpExit(404, ["title" => L10n::t('Page not found.')]);
+		throw new \Friendica\Network\HTTPException\NotFoundException();
 	}
 
 	$a->data['user'] = $user;
diff --git a/mod/viewsrc.php b/mod/viewsrc.php
index 939c73a14..55eb0b990 100644
--- a/mod/viewsrc.php
+++ b/mod/viewsrc.php
@@ -18,8 +18,7 @@ function viewsrc_content(App $a)
 	$item_id = (($a->argc > 1) ? intval($a->argv[1]) : 0);
 
 	if (!$item_id) {
-		notice(L10n::t('Item not found.') . EOL);
-		return;
+		throw new \Friendica\Network\HTTPException\NotFoundException(L10n::t('Item not found.'));
 	}
 
 	$item = Item::selectFirst(['body'], ['uid' => local_user(), 'id' => $item_id]);
diff --git a/src/BaseModule.php b/src/BaseModule.php
index 3878d1507..dd9059bfb 100644
--- a/src/BaseModule.php
+++ b/src/BaseModule.php
@@ -153,7 +153,7 @@ abstract class BaseModule extends BaseObject
 			Logger::log('checkFormSecurityToken failed: user ' . $a->user['guid'] . ' - form element ' . $typename);
 			Logger::log('checkFormSecurityToken failed: _REQUEST data: ' . print_r($_REQUEST, true), Logger::DATA);
 
-			System::httpExit(403);
+			throw new \Friendica\Network\HTTPException\ForbiddenException();
 		}
 	}
 }
diff --git a/src/Model/Profile.php b/src/Model/Profile.php
index 3c4ca6fed..13156a932 100644
--- a/src/Model/Profile.php
+++ b/src/Model/Profile.php
@@ -112,7 +112,6 @@ class Profile
 
 		if (!DBA::isResult($user) && empty($profiledata)) {
 			Logger::log('profile error: ' . $a->query_string, Logger::DEBUG);
-			notice(L10n::t('Requested account is not available.') . EOL);
 			return;
 		}
 
@@ -129,7 +128,6 @@ class Profile
 
 		if (empty($pdata) && empty($profiledata)) {
 			Logger::log('profile error: ' . $a->query_string, Logger::DEBUG);
-			notice(L10n::t('Requested profile is not available.') . EOL);
 			return;
 		}
 
diff --git a/src/Module/Attach.php b/src/Module/Attach.php
index 24e0edc55..e9af90fac 100644
--- a/src/Module/Attach.php
+++ b/src/Module/Attach.php
@@ -24,7 +24,7 @@ class Attach extends BaseModule
 	{
 		$a = self::getApp();
 		if ($a->argc != 2) {
-			System::httpExit(400); // Bad Request.
+			throw new \Friendica\Network\HTTPException\BadRequestException();
 		}
 
 		// @TODO: Replace with parameter from router
@@ -33,19 +33,19 @@ class Attach extends BaseModule
 		// Check for existence
 		$item = MAttach::exists(['id' => $item_id]);
 		if ($item === false) {
-			System::httpExit(404, ['description' => L10n::t('Item was not found.')]);
+			throw new \Friendica\Network\HTTPException\NotFoundException(L10n::t('Item was not found.'));
 		}
 
 		// Now we'll fetch the item, if we have enough permisson
 		$item = MAttach::getByIdWithPermission($item_id);
 		if ($item === false) {
-			System::httpExit(403, ['description' => L10n::t('Permission denied.')]);
+			throw new \Friendica\Network\HTTPException\ForbiddenException(L10n::t('Permission denied.'));
 		}
 
 		$data = MAttach::getData($item);
 		if (is_null($data)) {
 			Logger::log('NULL data for attachment with id ' . $item['id']);
-			System::httpExit(404, ['description' => L10n::t('Item was not found.')]);
+			throw new \Friendica\Network\HTTPException\NotFoundException(L10n::t('Item was not found.'));
 		}
 
 		// Use quotes around the filename to prevent a "multiple Content-Disposition"
diff --git a/src/Module/Feed.php b/src/Module/Feed.php
index eabd45da2..ba1b08596 100644
--- a/src/Module/Feed.php
+++ b/src/Module/Feed.php
@@ -33,7 +33,7 @@ class Feed extends BaseModule
 
 		// @TODO: Replace with parameter from router
 		if ($a->argc < 2) {
-			System::httpExit(400);
+			throw new \Friendica\Network\HTTPException\BadRequestException();
 		}
 
 		$type = null;
diff --git a/src/Module/Followers.php b/src/Module/Followers.php
index 9906dfc33..79f34021b 100644
--- a/src/Module/Followers.php
+++ b/src/Module/Followers.php
@@ -20,13 +20,13 @@ class Followers extends BaseModule
 
 		// @TODO: Replace with parameter from router
 		if (empty($a->argv[1])) {
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		// @TODO: Replace with parameter from router
 		$owner = User::getOwnerDataByNick($a->argv[1]);
 		if (empty($owner)) {
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		$page = defaults($_REQUEST, 'page', null);
diff --git a/src/Module/Following.php b/src/Module/Following.php
index 670142c48..3a68e7e0a 100644
--- a/src/Module/Following.php
+++ b/src/Module/Following.php
@@ -20,13 +20,13 @@ class Following extends BaseModule
 
 		// @TODO: Replace with parameter from router
 		if (empty($a->argv[1])) {
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		// @TODO: Replace with parameter from router
 		$owner = User::getOwnerDataByNick($a->argv[1]);
 		if (empty($owner)) {
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		$page = defaults($_REQUEST, 'page', null);
diff --git a/src/Module/Group.php b/src/Module/Group.php
index eb1389d79..acc969c7e 100644
--- a/src/Module/Group.php
+++ b/src/Module/Group.php
@@ -137,7 +137,7 @@ class Group extends BaseModule
 		$change = false;
 
 		if (!local_user()) {
-			System::httpExit(403);
+			throw new \Friendica\Network\HTTPException\ForbiddenException();
 		}
 
 		$a = self::getApp();
@@ -276,7 +276,7 @@ class Group extends BaseModule
 		}
 
 		if (!isset($group)) {
-			System::httpExit(400);
+			throw new \Friendica\Network\HTTPException\BadRequestException();
 		}
 
 		$groupeditor = [
diff --git a/src/Module/Inbox.php b/src/Module/Inbox.php
index 35160bd88..5367adb7e 100644
--- a/src/Module/Inbox.php
+++ b/src/Module/Inbox.php
@@ -25,7 +25,7 @@ class Inbox extends BaseModule
 		$postdata = file_get_contents('php://input');
 
 		if (empty($postdata)) {
-			System::httpExit(400);
+			throw new \Friendica\Network\HTTPException\BadRequestException();
 		}
 
 		if (Config::get('debug', 'ap_inbox_log')) {
@@ -43,7 +43,7 @@ class Inbox extends BaseModule
 		if (!empty($a->argv[1])) {
 			$user = DBA::selectFirst('user', ['uid'], ['nickname' => $a->argv[1]]);
 			if (!DBA::isResult($user)) {
-				System::httpExit(404);
+				throw new \Friendica\Network\HTTPException\NotFoundException();
 			}
 			$uid = $user['uid'];
 		} else {
@@ -52,6 +52,6 @@ class Inbox extends BaseModule
 
 		ActivityPub\Receiver::processInbox($postdata, $_SERVER, $uid);
 
-		System::httpExit(202);
+		throw new \Friendica\Network\HTTPException\AcceptedException();
 	}
 }
diff --git a/src/Module/Install.php b/src/Module/Install.php
index 1cef8fbaf..eae018fe1 100644
--- a/src/Module/Install.php
+++ b/src/Module/Install.php
@@ -51,7 +51,7 @@ class Install extends BaseModule
 		$a = self::getApp();
 
 		if (!$a->getMode()->isInstall()) {
-			Core\System::httpExit(403);
+			throw new \Friendica\Network\HTTPException\ForbiddenException();
 		}
 
 		// route: install/testrwrite
@@ -59,7 +59,7 @@ class Install extends BaseModule
 		// @TODO: Replace with parameter from router
 		if ($a->getArgumentValue(1, '') == 'testrewrite') {
 			// Status Code 204 means that it worked without content
-			Core\System::httpExit(204);
+			throw new \Friendica\Network\HTTPException\NoContentException();
 		}
 
 		self::$installer = new Core\Installer();
diff --git a/src/Module/NodeInfo.php b/src/Module/NodeInfo.php
index c8d75b8e1..3261ef690 100644
--- a/src/Module/NodeInfo.php
+++ b/src/Module/NodeInfo.php
@@ -18,7 +18,7 @@ class NodeInfo extends BaseModule
 		$config = self::getApp()->getConfig();
 
 		if (!$config->get('system', 'nodeinfo')) {
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 	}
 
@@ -41,14 +41,14 @@ class NodeInfo extends BaseModule
 	 *
 	 * @param App $app
 	 *
-	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
+	 * @throws \Friendica\Network\HTTPException\NotFoundException
 	 */
 	private static function printWellKnown(App $app)
 	{
 		$config = $app->getConfig();
 
 		if (!$config->get('system', 'nodeinfo')) {
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		$nodeinfo = [
diff --git a/src/Module/Objects.php b/src/Module/Objects.php
index f34af3a08..2104e8042 100644
--- a/src/Module/Objects.php
+++ b/src/Module/Objects.php
@@ -20,7 +20,7 @@ class Objects extends BaseModule
 		$a = self::getApp();
 
 		if (empty($a->argv[1])) {
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		if (!ActivityPub::isRequest()) {
@@ -38,7 +38,7 @@ class Objects extends BaseModule
 			// @TODO: Replace with parameter from router
 			$item = Item::selectFirst(['id', 'author-link'], ['guid' => $a->argv[1], 'private' => false]);
 			if (!DBA::isResult($item) || !strstr($item['author-link'], System::baseUrl())) {
-				System::httpExit(404);
+				throw new \Friendica\Network\HTTPException\NotFoundException();
 			}
 		}
 
diff --git a/src/Module/Outbox.php b/src/Module/Outbox.php
index 27dcd5c1f..148256779 100644
--- a/src/Module/Outbox.php
+++ b/src/Module/Outbox.php
@@ -20,12 +20,12 @@ class Outbox extends BaseModule
 
 		// @TODO: Replace with parameter from router
 		if (empty($a->argv[1])) {
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		$owner = User::getOwnerDataByNick($a->argv[1]);
 		if (empty($owner)) {
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		$page = defaults($_REQUEST, 'page', null);
diff --git a/src/Module/Photo.php b/src/Module/Photo.php
index 9165af8be..bcfe13f53 100644
--- a/src/Module/Photo.php
+++ b/src/Module/Photo.php
@@ -6,6 +6,7 @@
 namespace Friendica\Module;
 
 use Friendica\BaseModule;
+use Friendica\Core\L10n;
 use Friendica\Core\Logger;
 use Friendica\Core\System;
 use Friendica\Model\Photo as MPhoto;
@@ -27,7 +28,7 @@ class Photo extends BaseModule
 		$a = self::getApp();
 		// @TODO: Replace with parameter from router
 		if ($a->argc <= 1 || $a->argc > 4) {
-			System::httpExit(400);
+			throw new \Friendica\Network\HTTPException\BadRequestException();
 		}
 
 		if (isset($_SERVER["HTTP_IF_MODIFIED_SINCE"])) {
@@ -74,9 +75,7 @@ class Photo extends BaseModule
 		}
 
 		if ($photo === false) {
-			// not using System::httpExit() because we don't want html here.
-			header($_SERVER["SERVER_PROTOCOL"] . " 404 Not Found" , true, 404);
-			exit();
+			System::httpExit('404', 'Not Found');
 		}
 
 		$cacheable = ($photo["allow_cid"] . $photo["allow_gid"] . $photo["deny_cid"] . $photo["deny_gid"] === "") && (isset($photo["cacheable"]) ? $photo["cacheable"] : true);
@@ -85,7 +84,7 @@ class Photo extends BaseModule
 
 		if (is_null($img) || !$img->isValid()) {
 			Logger::log("Invalid photo with id {$photo["id"]}.");
-			System::httpExit(500, ["description" => "Invalid photo with id {$photo["id"]}."]);
+			throw new \Friendica\Network\HTTPException\InternalServerErrorException(L10n::t('Invalid photo with id %s.', $photo["id"]));
 		}
 
 		// if customsize is set and image is not a gif, resize it
diff --git a/src/Module/Profile.php b/src/Module/Profile.php
index c3297d261..fceea726b 100644
--- a/src/Module/Profile.php
+++ b/src/Module/Profile.php
@@ -38,7 +38,7 @@ class Profile extends BaseModule
 
 		// @TODO: Replace with parameter from router
 		if ($a->argc < 2) {
-			System::httpExit(400);
+			throw new \Friendica\Network\HTTPException\BadRequestException();
 		}
 
 		self::$which = filter_var($a->argv[1], FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_LOW | FILTER_FLAG_STRIP_HIGH | FILTER_FLAG_STRIP_BACKTICK);
diff --git a/src/Module/Proxy.php b/src/Module/Proxy.php
index 387667a1a..75a1142af 100644
--- a/src/Module/Proxy.php
+++ b/src/Module/Proxy.php
@@ -70,7 +70,7 @@ class Proxy extends BaseModule
 		$request = self::getRequestInfo();
 
 		if (empty($request['url'])) {
-			System::httpExit(400, ['title' => L10n::t('Bad Request.')]);
+			throw new \Friendica\Network\HTTPException\BadRequestException();
 		}
 
 		// Webserver already tried direct cache...
diff --git a/src/Module/Statistics.php b/src/Module/Statistics.php
index 566ace333..3e64828e7 100644
--- a/src/Module/Statistics.php
+++ b/src/Module/Statistics.php
@@ -13,7 +13,7 @@ class Statistics extends BaseModule
 		$config = self::getApp()->getConfig();
 
 		if (!$config->get("system", "nodeinfo")) {
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 	}
 
diff --git a/src/Module/WebFinger.php b/src/Module/WebFinger.php
index 3afcecb05..0c1a692e1 100644
--- a/src/Module/WebFinger.php
+++ b/src/Module/WebFinger.php
@@ -5,7 +5,6 @@ namespace Friendica\Module;
 use Friendica\BaseModule;
 use Friendica\Core\L10n;
 use Friendica\Core\Renderer;
-use Friendica\Core\System;
 use Friendica\Network\Probe;
 
 /**
@@ -13,22 +12,14 @@ use Friendica\Network\Probe;
  */
 class WebFinger extends BaseModule
 {
-	public static function init()
-	{
-		if (!local_user()) {
-			System::httpExit(
-				403,
-				[
-					'title'       => L10n::t('Public access denied.'),
-					'description' => L10n::t('Only logged in users are permitted to perform a probing.'),
-				],
-			);
-			exit();
-		}
-	}
-
 	public static function content()
 	{
+		if (!local_user()) {
+			$e = new \Friendica\Network\HTTPException\ForbiddenException(L10n::t("Only logged in users are permitted to perform a probing."));
+			$e->httpdesc = L10n::t("Public access denied.");
+			throw $e;
+		}
+
 		$app = self::getApp();
 
 		$addr = defaults($_GET, 'addr', '');
diff --git a/src/Module/Xrd.php b/src/Module/Xrd.php
index 38ce151ff..a3b161d18 100644
--- a/src/Module/Xrd.php
+++ b/src/Module/Xrd.php
@@ -58,7 +58,7 @@ class Xrd extends BaseModule
 		$user = User::getByNickname($name);
 
 		if (empty($user)) {
-			System::httpExit(404);
+			throw new \Friendica\Network\HTTPException\NotFoundException();
 		}
 
 		$profileURL = $app->getBaseURL() . '/profile/' . $user['nickname'];
diff --git a/src/Protocol/Diaspora.php b/src/Protocol/Diaspora.php
index 33cbb2659..3a7e73cee 100644
--- a/src/Protocol/Diaspora.php
+++ b/src/Protocol/Diaspora.php
@@ -400,7 +400,7 @@ class Diaspora
 				if ($no_exit) {
 					return false;
 				} else {
-					System::httpExit(400);
+					throw new \Friendica\Network\HTTPException\BadRequestException();
 				}
 			}
 
@@ -419,7 +419,7 @@ class Diaspora
 			if ($no_exit) {
 				return false;
 			} else {
-				System::httpExit(400);
+				throw new \Friendica\Network\HTTPException\BadRequestException();
 			}
 		}
 
@@ -445,7 +445,7 @@ class Diaspora
 			if ($no_exit) {
 				return false;
 			} else {
-				System::httpExit(400);
+				throw new \Friendica\Network\HTTPException\BadRequestException();
 			}
 		}
 
@@ -455,7 +455,7 @@ class Diaspora
 			if ($no_exit) {
 				return false;
 			} else {
-				System::httpExit(400);
+				throw new \Friendica\Network\HTTPException\BadRequestException();
 			}
 		}
 
@@ -465,7 +465,7 @@ class Diaspora
 			if ($no_exit) {
 				return false;
 			} else {
-				System::httpExit(400);
+				throw new \Friendica\Network\HTTPException\BadRequestException();
 			}
 		}
 
@@ -550,7 +550,7 @@ class Diaspora
 
 		if (!$base) {
 			Logger::log('unable to locate salmon data in xml');
-			System::httpExit(400);
+			throw new \Friendica\Network\HTTPException\BadRequestException();
 		}
 
 
@@ -588,7 +588,7 @@ class Diaspora
 
 		if (!$author_link) {
 			Logger::log('Could not retrieve author URI.');
-			System::httpExit(400);
+			throw new \Friendica\Network\HTTPException\BadRequestException();
 		}
 		// Once we have the author URI, go to the web and try to find their public key
 		// (first this will look it up locally if it is in the fcontact cache)
@@ -599,14 +599,14 @@ class Diaspora
 
 		if (!$key) {
 			Logger::log('Could not retrieve author key.');
-			System::httpExit(400);
+			throw new \Friendica\Network\HTTPException\BadRequestException();
 		}
 
 		$verify = Crypto::rsaVerify($signed_data, $signature, $key);
 
 		if (!$verify) {
 			Logger::log('Message did not verify. Discarding.');
-			System::httpExit(400);
+			throw new \Friendica\Network\HTTPException\BadRequestException();
 		}
 
 		Logger::log('Message verified.');