> I think you could more or less instaban users who mention Telegram and nothing of value would be lost.

Oh for sure. But they'd just switch to saying "†e|_e gr@mm" or something. It does seem to me like the cheapest models today should be cheap and good enough to finally kill off this type of spam, though, if deployed correctly.

My preference would be that spam comments detected in this way get a bit set on them that causes them to be visible only to their posters, and posting more than one just causes all your future comments to also get that bit regardless of their content, but since it's a shadowban, it's harder for spammers to know that their account is burned.