I have to agree with Band on the Run. Once as lay leader at a UMC, I had to eject a member of the youth. He was supplying guns, knives, and tabacco to other youth. One gun ended up in a school. Luckily, no one got hurt.
I had a heart-to-heart talk with the kid first and actually got through his thick skull that this crap needed to end. Unfortunately, he went home to Mom and cried that I was being mean. She read me the riot act, and I kicked him out over the objections of the pastor. Enough was enough. Ironically, I actually helped the kid who brought the gun to school. He instantly realized that it was an incredibly dumb thing to do, and his parents asked for my support. The kid has since gotten his life completely turned around. (Funny how a a few nights in jail will make a kid really comtemplate their actions.)
There is one big difference between my actions and the JW. I never told anyone that they had to shun the kid that got kicked out. Quite the opposite, I intended to pull him back in after everyone had had some time to think about it for a while. Unfortunately, I left that church before I ever got a chance to do so.
There was no emotional black mail trying to seperate him from family and friends. Just an honest attempt to keep the other youth under my care safe.