OK, that sounds more reasonable. The help page made it sound that unable to remove for not being uploaded by oneself - therefore have no archive ID or account to associate with was the most likely response.

Mostly I appreciate hugely what archive.org does, though like the root comment, I'm much less keen on ephemeral social networks preserved. Especially as most users will never see an announcement on a specialised reddit sub or HN, so will never know it wasn't all deleted like Google announced. Yes, I know it's not sensible to rely on no copies, but most naive users probably assume that. :)