So to avoid this becoming another "Decline of civility" thread, I'm not going to post names... but I'm in a game now (on Isotropic) where the user had a problem with the fact that I played Scrying Pool, so in response he told me that he's going to purposefully play his last turn slow; and just sit there doing nothing for the next hour except keeping himself from timing out by playing and undoing a Copper.
If I were to exit the game, then I give players the ability to raise their rank simply by being complete jerks. Sure I can avoid this specific user in the future, but that's really not enough.
I have no good answers here at all. I understand the problems with blacklist threads, or voting on whether you like a user or not. But there needs to be some formal way to deal with this type of stuff on Goko. Perhaps simply a moderator/admin that can be contacted to report such behavior? A warning after the first occurrence, banning if it continues? Hopefully they would have the ability to look at logs of either chats or the games to prove that this had happened if it did.
Update... while I was posting this, the guy gave up and ended his turn; I won next turn. Quite possibly he thought that I had gone away from the computer and was hoping to win by timeout.