Where does your right to force others to a drug screening come from? Why is your right to be comforted higher than the right of the teens not to have a drug screening? It comes from people voting democratically for representatives who pass it into law, providing that such in not unconstitutional - just like every other law in this nation. Given that it's not unconsitutional (it isn't, according to the Supreme court), where does a teen have the right not to have a drug screening?
Here's another thought, SkyRat. We routinely insist on testing airline pilots for drugs before they're allowed to fly. Unconstitutional? Invasive? Taking away the rights of airline pilots?