A person shows up in a room full of random people. Punches one in the face and starts swinging at everyone else. People instinctively start to defend themselves and, as they are more numerous, overwhelm and badly wound the instigator. OP walks into the room, "everyone in this room is so violent, look everyone, they are so violent". People outside the room hearing OP, "yeah, I bet anyone like them is just as violent".