Association with darknet markets seems to get a lot more attention. Something also tells me that mixers aren't doing the sort of taint analysis that Chainalysis or Ciphertrace does.
If I were operating one I'd be keeping an eye on the hottest addresses. It's almost inevitable they'll pay you a visit.
Aiding privacy and allowing druggists to get by is fine by me. No way would I want my service to allow known thieves to get away clean but that's me.
A mixer that blacklists or steals "tainted" outputs could never be trusted. The only honest way to run a mixer is to treat bitcoins as fully fungible. I think once you start injecting your own ethics like that, you're entering muddy waters.
From a rational viewpoint, law enforcement has made far more busts in the DNM sector -- Silk Road, Alphabay, Hansa, Wall Street Market, Valhalla, the list goes on.
They even went after Deep Dot Web earlier this year. For that reason, I reckon mixers willing to serve dark web customers are willing to serve
anybody.
I can't imagine the likes of the US government caring about Binance losing 7,000 bitcoins either. There were no US victims so they have absolutely no reason to lift a finger.