Comment by chmod775

There's servers where they just hang out, but which themselves are legitimate. Cybersecurity related ones etc. You can ban them and they'll just switch to another account within a minute. Occasionally discord or a server owner does, but everyone knows its pointless. There's probably other servers that are mostly used by cybercriminals, maybe command-and-control backups, and security researchers may stumble upon these when taking some malware apart, join them, and end up getting in contact with the owner.

In general I don't think law enforcement wants discord to take these down or ban them. These guys would have no problem to just make some IRC servers or whatever to hang out on instead, which would be much harder to surveil for law enforcement - compared to discord just forwarding them everything said by those accounts and on those servers.