diff --git a/keyserver/src/fetchers/upload-fetchers.js b/keyserver/src/fetchers/upload-fetchers.js
--- a/keyserver/src/fetchers/upload-fetchers.js
+++ b/keyserver/src/fetchers/upload-fetchers.js
@@ -146,7 +146,9 @@
   };
 }
 
-async function fetchImages(
+// This function technically fetches all kinds of unassigned media,
+// but it's only called by legacy clients that only support images
+async function fetchUnassignedImages(
   viewer: Viewer,
   mediaIDs: $ReadOnlyArray<string>,
 ): Promise<$ReadOnlyArray<Media>> {
@@ -154,7 +156,10 @@
     SELECT id AS uploadID, secret AS uploadSecret,
       type AS uploadType, extra AS uploadExtra
     FROM uploads
-    WHERE id IN (${mediaIDs}) AND uploader = ${viewer.id} AND container IS NULL
+    WHERE id IN (${mediaIDs})
+      AND uploader = ${viewer.id}
+      AND container IS NULL
+      AND user_container IS NULL
   `;
   const [result] = await dbQuery(query);
   return result.map(imagesFromRow);
@@ -279,7 +284,7 @@
   return { media };
 }
 
-async function fetchUploadsForMessage(
+async function fetchUnassignedUploadsForMessage(
   viewer: Viewer,
   mediaMessageContents: $ReadOnlyArray<MediaMessageServerDBContent>,
 ): Promise<$ReadOnlyArray<Object>> {
@@ -289,18 +294,24 @@
     SELECT id AS uploadID, secret AS uploadSecret,
       type AS uploadType, extra AS uploadExtra
     FROM uploads
-    WHERE id IN (${uploadIDs}) AND uploader = ${viewer.id} AND container IS NULL
+    WHERE id IN (${uploadIDs})
+      AND uploader = ${viewer.id}
+      AND container IS NULL
+      AND user_container IS NULL
   `;
 
   const [uploads] = await dbQuery(query);
   return uploads;
 }
 
-async function fetchMediaFromMediaMessageContent(
+async function fetchUnassignedMediaFromMediaMessageContent(
   viewer: Viewer,
   mediaMessageContents: $ReadOnlyArray<MediaMessageServerDBContent>,
 ): Promise<$ReadOnlyArray<Media>> {
-  const uploads = await fetchUploadsForMessage(viewer, mediaMessageContents);
+  const uploads = await fetchUnassignedUploadsForMessage(
+    viewer,
+    mediaMessageContents,
+  );
 
   return constructMediaFromMediaMessageContentsAndUploadRows(
     mediaMessageContents,
@@ -401,8 +412,8 @@
   getUploadURL,
   makeUploadURI,
   imagesFromRow,
-  fetchImages,
+  fetchUnassignedImages,
   fetchMediaForThread,
-  fetchMediaFromMediaMessageContent,
+  fetchUnassignedMediaFromMediaMessageContent,
   constructMediaFromMediaMessageContentsAndUploadRows,
 };
diff --git a/keyserver/src/responders/message-responders.js b/keyserver/src/responders/message-responders.js
--- a/keyserver/src/responders/message-responders.js
+++ b/keyserver/src/responders/message-responders.js
@@ -51,8 +51,8 @@
 import { fetchServerThreadInfos } from '../fetchers/thread-fetchers.js';
 import { checkThreadPermission } from '../fetchers/thread-permission-fetchers.js';
 import {
-  fetchImages,
-  fetchMediaFromMediaMessageContent,
+  fetchUnassignedImages,
+  fetchUnassignedMediaFromMediaMessageContent,
 } from '../fetchers/upload-fetchers.js';
 import { fetchKnownUserInfos } from '../fetchers/user-fetchers.js';
 import type { Viewer } from '../session/viewer.js';
@@ -178,8 +178,11 @@
     localID,
   );
   const mediaPromise: Promise<$ReadOnlyArray<Media>> = request.mediaIDs
-    ? fetchImages(viewer, request.mediaIDs)
-    : fetchMediaFromMediaMessageContent(viewer, request.mediaMessageContents);
+    ? fetchUnassignedImages(viewer, request.mediaIDs)
+    : fetchUnassignedMediaFromMediaMessageContent(
+        viewer,
+        request.mediaMessageContents,
+      );
 
   const [existingMessageInfo, media] = await Promise.all([
     existingMessageInfoPromise,