In a recent game thread KA1Z3R posted about 50 pictures. I was going through the game thread afterwards, just skimming it, when I noticed the picture of the girl in a thong. At the time the community guidelines hadn't been posted, but anyone who comes here as often as KA1Z3R definitely knew this was against the rules. I deleted the photo and kept skimming. I came across at least two more photos that I considered totally inappropriate. I'm not going to get into the what they depicted.
I decided to warn KA1Z3R and hide all his comments until I could finish going through the rest of the thread. At the time I didn't know that the only way to unhide the comments is to do so one by one. That's why all the photos from that thread appear to be deleted. They're actually just hidden.
He's not banned, and since the official guidelines weren't posted until after that game thread, he doesn't even technically have a warning.
Lastly, the only people I have ever banned were obvious trolls.