Did you meet a user here from the threads who turned out to be surprisingly unfriendly?

Did you ever meet a user who only had toxic, negative interactions with you? Or someone who started off friendly but turned out to be not friendly at all? Someone who surprised with you how rotten and foul their personality actually turned out to be? Someone who wouldn't lift a finger to save your life or do any good for you? Someone who labled you with hateful terms or called you names or cursed at you?