Chances are, if there's a known cheater on the leaderboard, we already know about it. There is a number of potential enforcement actions that we can take, some of which may be visible to you and some of which are not. It may be that we're trying to convince him to stop cheating and come to the side of Righteousness, Truth, and Unicorns. It could be that we're conducting our own research by watching him to learn what new tricks he has — banning him immediately would deprive us of that knowledge. We're sneaky like that.
Either way, know this: our trust and safety team is very, very good. They've recovered millions of fraudulently earned points and prevented payouts to many fake accounts. And even when the fraudsters manage to collect, it's not because we don't know — it's because we're watching and learning. And it turns out, most of them are really bad at being fraudsters.