With our older 3 (all 18 + now) we took away all the screens first, then the door, then the other personal belongings. Never had to raise our voice, or go beyond that. We did make sure there was a direct connection between the offense and the restriction, "clearly you're overstimulated or you wouldn't act like that."
Ultimately we gave up commercial television in all forms, with a restriction of no more than an hour of screen time a day during the school year.
It really did help. We noticed we had more problems with certain programs and the kids' grip on what reality looks like. Still do, but I can't take away a 19 year old's television and computer. ;o)
Our most gifted, and youngest child needs to lose screens for longer and sooner to keep the 'tude in check.
HTH
Bean
