[tafycent]

Let's say you generate the identifier for the upload based on the file hash. If you add a timestamp or random nonce then they'll have to redistribute the link to the file every time they re-upload as it will change every time.

[gorbypark]

Exactly. Nothing would stop someone from re-uploading it, but they'd end up with a different url which would go dead pretty quick if used to share something publicly.