diff --git a/ext/not_a_tag/main.php b/ext/not_a_tag/main.php
index 74f5dbf0..c73df2f4 100644
--- a/ext/not_a_tag/main.php
+++ b/ext/not_a_tag/main.php
@@ -55,7 +55,12 @@ class NotATag extends Extension
 
     public function onTagSet(TagSetEvent $event)
     {
-        $this->scan($event->tags);
+        global $user;
+        if ($user->can(Permissions::BAN_IMAGE)) {
+            $event->tags = $this->strip($event->tags);
+        } else {
+            $this->scan($event->tags);
+        }
     }
 
     /**
@@ -70,17 +75,36 @@ class NotATag extends Extension
             $tags[] = strtolower($tag);
         }
 
-        $pairs = $database->get_all("SELECT * FROM untags");
-        foreach ($pairs as $tag_url) {
-            $tag = strtolower($tag_url[0]);
-            $url = $tag_url[1];
-            if (in_array($tag, $tags)) {
-                header("Location: $url");
-                exit; # FIXME: need a better way of aborting the tag-set or upload
+        $pairs = $database->get_pairs("SELECT LOWER(tag), redirect FROM untags");
+        foreach ($pairs as $tag => $url) {
+            if (in_array(strtolower($tag), $tags)) {
+                throw new TagSetException("Invalid tag used: $tag", $url);
             }
         }
     }
 
+    /**
+     * #param string[] $tags
+     */
+    private function strip(array $tags): array
+    {
+        global $database;
+        $untags = $database->get_col("SELECT LOWER(tag) FROM untags");
+
+        $ok_tags = [];
+        foreach ($tags as $tag) {
+            if (!in_array(strtolower($tag), $untags)) {
+                $ok_tags[] = $tag;
+            }
+        }
+
+        if (count($ok_tags) == 0) {
+            $ok_tags = ["tagme"];
+        }
+
+        return $ok_tags;
+    }
+
     public function onPageSubNavBuilding(PageSubNavBuildingEvent $event)
     {
         global $user;
diff --git a/ext/tag_edit/main.php b/ext/tag_edit/main.php
index df87e9a2..a080da62 100644
--- a/ext/tag_edit/main.php
+++ b/ext/tag_edit/main.php
@@ -38,6 +38,17 @@ class SourceSetEvent extends Event
 }
 
 
+class TagSetException extends SCoreException
+{
+    public $redirect;
+
+    public function __construct(string $msg, ?string $redirect = null)
+    {
+        parent::__construct($msg, null);
+        $this->redirect = $redirect;
+    }
+}
+
 class TagSetEvent extends Event
 {
     /** @var Image */
@@ -162,7 +173,7 @@ class TagEdit extends Extension
 
     public function onImageInfoSet(ImageInfoSetEvent $event)
     {
-        global $user;
+        global $page, $user;
         if ($user->can(Permissions::EDIT_IMAGE_OWNER) && isset($_POST['tag_edit__owner'])) {
             $owner = User::by_name($_POST['tag_edit__owner']);
             if ($owner instanceof User) {
@@ -172,7 +183,15 @@ class TagEdit extends Extension
             }
         }
         if ($user->can(Permissions::EDIT_IMAGE_TAG) && isset($_POST['tag_edit__tags'])) {
-            send_event(new TagSetEvent($event->image, Tag::explode($_POST['tag_edit__tags'])));
+            try {
+                send_event(new TagSetEvent($event->image, Tag::explode($_POST['tag_edit__tags'])));
+            } catch (TagSetException $e) {
+                if ($e->redirect) {
+                    $page->flash("{$e->getMessage()}, please see {$e->redirect}");
+                } else {
+                    $page->flash($e->getMessage());
+                }
+            }
         }
         if ($user->can(Permissions::EDIT_IMAGE_SOURCE) && isset($_POST['tag_edit__source'])) {
             if (isset($_POST['tag_edit__tags']) ? !preg_match('/source[=|:]/', $_POST["tag_edit__tags"]) : true) {