The kids on Scared Straight "ain't" on TV to be famous. The families involved have to jump through some hoops to have their kids on the show; everyone has to sign stuff, as Aux Arcs has stated. They've created a reality TV show around bad kids, hopefully to scare them straight so they will behave and quit being in trouble. I believe in order to be on the show you have to meet certain requirements. You should probably check out their website for further details.
