Punishing students who have committed no offense by submitting having them yank out their hair or pee in cups once a week and worry if the nyquil they drank last night or the marajuana brownie their big brother fed them as a joke is going to get them kicked out of school.
We shouldn't be treating schools like hotbeds for criminal activity. If there is reason to suspect someone, go from there. Making every single student submit to a potentially humiliating and totally unwarranted breech of privacy simply out of policy is inane.
What next? Accessing our google search histories to see if we've ever cheated on our homework online, lied about our age on myspace or talked about shooting teachers? Kicking kids out of school for singing "light a match and watch it burn" (something we've been singing for YEARS and YEARS)? ...though I suppose some schools are already doing this stuff...
People need to stop jumping at shadows. Shit happens. It always has and it always will. We can't protect our children from THEMSELVES. They need to make mistakes, learn from them and be accountable for them as inviduals. Treating our kids like criminals or hubcaps coming out of an assemblyline isn't doing anyone any favors. Nor is hyperventalating at every potential danger to them ("anon", jenkem, huffing magic markers, choking on bottle caps, wheels in their shoes, snowboarding, toad-licking, etc. etc.) isn't going to help: it's only going to create a more frightening, oppressive and (dare I say) facist enviornment in which to grow up.
Kids NEED to make mistakes to learn how to live their lives.
The answer isn't making it impossible for them to make mistakes... it's making them accountable when they're caught.