I'd like for communities to be able to opt in to a feature that shadowbans new accounts for a brief period of time. Moderators should be able to release accounts from the shadowban manually; they should also be released from the shadowban after the time period expires.
The initial duration can be quite short—an hour, maybe?—but ‘suspicious activity’, definition TBD but with some suggestions below, should rapidly increase the duration of the shadowban (say by doubling it for each red flag).
This would help prevent users who have been subject to other sorts of anti-abuse moderation (like STAT) from simply creating new accounts on new IP addresses and continuing their existing patterns of behavior. Across Codidact, we have, to my knowledge, exactly one user who does this, and does it frequently, and I would like it to stop once and for all.
**Edit:** The value of a short shadowban has been questioned in one answer, and ironically enough the motivation I had for that is in line with a different answer: the idea is to give the suspicious user enough rope to incriminate himself. Post once, and your post appears to the rest of the world in an hour. Post again before that hour is up, with some red flags in the second post, and now the ban is extended, and *both* posts remain hidden from the world for longer. This is better than a rate limit, because it lets us see the true colors of the suspicious user faster. And it's better than not imposing the shadowban at all initially, because there is no interval during which other users can be distracted by the posts that would be retroactively obliterated if the new user is successfully re-exiled.
Of course this is all predicated on moderators taking an active role in responding to new activity and firmly rejecting ban-evading accounts; nothing I could propose can substitute for that. But if I were such a moderator, I would want a tool like this to make it so that I can keep the community clean without having to watch it 24/7 for sneaky ban evaders.
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Suggestions for ‘suspicious activity’:
* Posting multiple questions all at once
* Questions that are unusually short
* Per-community lists of suspicious words—I can be 99.99% certain that any new account in the Mathematics community that posts a question with the words ‘pictorialize’ or ‘soothsay’, for example, is That Guy
