Somebody has mentioned this about Patreon before. But couldn't a drug dealer now just sign up to Twitter and get Tips from their customers instead of cash?
It's probable that drug dealers could use this, but there's a bit of a marketing hurdle if they do decide to go that route. Can you imagine the awkwardness of explaining that you want funds received through Twitter? It's a nightmare since twitter is a public arena and doesn't even use E2E encryption for its DMs, so police can have a nose at your convos.