You are dodging the issue.

You are taking user’s media files and uploading to *your* cdn.

You are now in control of the media displayed on primal not the user.

If the user changes the media associated with their media url (not the url just the media) primal would be displaying incorrect / out of date content.

Primal at any point could change the content associated with its media links.

The charade of ignorance on this subject is alarming.