You currently cannot restrict access to files with "public" permissions. Presently, a website I own will be linking to images and other files, directly using DO Spaces. This however, means that ANYONE can link to these files or download them .
The feature request is to provide a method to restrict access for public files, to only certain domains/ips which deliver the content. This could be a global setting for the spaces, or optionally for individual files/folders.
example.com is in the allowed list, so hotlinking/direct linking to public files is allowed, however otherexample.com is not in the allowed list, so they cannot deliver these files.
There should also be a setting to prevent direct access, and maybe allow all sites "other" than specific blocked sites (this would be good in the event that you want to allow others to hotlink your files, but only want to restrict/block access to certain bad third-parties).