some even hide behind gimmicks "BigSteve2112" 

bigsteve the resident headlock vigilante

in america, chances are ,if this was tried,the follwoing would have happend,ill take the op story and change the scenario for realistic aproach:
I'm a big FATSO so naturally people LAUGH AT me at times. There is a dude(dad) who works at a machine shop who has been coming home and smacking around his girlfriend. Her cousin who is a wimp approached me and asked me to go down and have a chat with the guy. So I go down to their apartment and knock on the door.(shotgun blast through the door) The dude opens the door all angry and shirtless covered in tattoos and when he sees my fat immdiately he cringes. I ordered him to put a shirt on when he's talking to me. He comes back(holding a gun) and asks what's up. I told him(that i rang the wrong doorbell aparently im just selling vacuum cleners) I'm a friend of his girl's family and if I hear anymore stories of him smacking her around I'm coming back and it's going to get ugly. So he gets pissed and starts trying to say something pokes his finger into my chest. I grabbed him and outmuscled him, put him in a headlock and squeezed pretty hard. I dropped him on the floor and repeated if I have to come back it's going to get ugly.
the capslock and brackets are how itd pan out