Well, in terms of online, I think it is hard to do unless you are on a Discord call or something. I'm not much of a poker player, but what is the benefit of having collusion? Most likely, it is to gang up on one player? I mean, that's just really unfair.

I don't think any technology right now is capable of detecting that because there are different connections to a game, maybe just randomized to joining of games or something.