How do I get rid of them without truble?

Over the last month during my lunch period these four random metal freaks sat at my table. No one really cared at first because they sat at the far end but like two days into them coming they started to scream beat on the table and shake their heads like a couple of fags! This really annoyed everyone else so My girl friend asked me to tell them to leave. I asked them and the one called me a whiny Lurch looking motherf&cker. I was angry but let it go because I didn't want to get suspended for doing something stupid. Anyway this is still going on and we have come to deal with it untill Tusday when I set my backpack down at the table to go buy lunch and I look back to see the one guy throw it on the ground about 10 feet away. I rushed over to him grabbed him by the hair and told him that if I ever see him touch my stuff agian His face will be imprinted on the table. The problem is I think because of what I did in rage that they will never leave. Also for us all to move is not an option. Any suggestions as to how to get them away? I'm the only one who will say anything so out of 12 people it's really more like 1 vs 4.