Okay popo... so 4 guys are going to sit in together at a 6-Max table? Possible but seems unlikely (if they were going to collude.. why would they do it with 4 of them on a 6-max table?... isn't that perhaps too many??).
For sure you'll get players colluding on tables, most often done via I.M. or even telephone. I was watching a guy play the other night (who I know from a poker forum
, don't know him well but do know he took down the Fifty-Fity just recently and was curious to see what tables he was playing on with his recent bankroll addition), he was on .50/1.00 Omaha 6-max table and oddly enough, the exact same player was sitting to his left on both tables... even more odd was when I'd been railing this guy in the 50-50, this same 'other guy' was there railing too and then introduced himself as this guy's buddy from same hometown.
I watched the table a bit, to observe what they were doing (not saying anything in the chat). I considered writing into support simply for the fact that I felt bad for the other players on the table (they were both sitting fairly deep) but then thought, "What if they're not? What if buddy just managed to sit down on each of the tables, getting position on his buddy in hopes of phucking him over? What if it was just some friendly rivalry going on?" I only watched a few hands and then left but it did stick with me (obviously or wouldn't write it right now).
I'm sure you'll get colluders fairly often on cash tables but not so often in sngs (although I've seen and reported it there and had support take care of it pronto... which was great.. on Fulltilt). Personally I've never detected it happening against myself on a cash table (not to say it couldn't have been going on but I think I would've picked up on it, as would most half decent players).
Nice post re: Stars support above. For sure the sites do their utmost to take care of this stuff. I know the couple of times I reported players colluding on sngs, they were dealt with right away (I know this for fact because they accidentally froze the wrong account,... my friend's account as I was watching their game and the colluders were even bold enough to collude openly in the chat box,... support shut down my friend's account by accident (lol) but fixed that up pronto as well... in other case I'd try a player search on said colluders and never saw them on a table again).