When users upload content via the Speaker Portal, the system creates a media item for each upload (either files or links). 

The sessions link to media items. If a session is deleted, nothing links to the media item anymore. The media item is still part of your dataset. If you must remove it, you can delete the media item via the Conference App Builder.

How to delete a media item

1. In the CMS, open the Media menu on the left and click on Media Data
2. Use the search tab and search for the session/presentation title of the session/presentation you deleted.
   (Media items receive the session/presentation title as their label)
3. Click the trashcan icon on the right of the item
4. Publish a data update