I once accidentally exposed a sock when someone mentioned somebody who was always talking about Hawaii with a “l”. I pointed out that she probably was thinking of Didi44. Turns out that Didi44 and lyngui were the same person. But their posting styles and repeated subjects were distinctive and obvious enough that while I knew it was the same person I didn’t even notice that he was using two different names. (He was a perfectly cromulent user, not a troll.)