Personally, no I don't worry about it. Sometimes I've ended up playing the same 5 people on a few different tables at the same time.
That's just what happens when everyone wants to play more than one table at a time to get more hands in.
I can understand watching for collusion... but I've never felt like I was being colluded against. And if they are they're very bad at it.
In general, bitcoiners are bad poker players. I walked away up at least $80 and don't plan on returning because even though hackers are bad poker players, they still have the upper hand by cheating.
I'm willing to bet you are one of the people who is involved in collusion on the site otherwise you wouldn't be so pro-cheater.
Alright, I was actually tryin to help you out and answer your question but I guess you already have your mind made up.
Good luck.