Illegal Activities, and our School

I just walked up into our middle school to use the restroom, and I noticed all of their "drug-free" posters, telling the harmful effects, the risks you're taking, and just overall that it's bad.  I look around our high school, and I haven't seen any of these.  It's like they've decided that we're in high school and we aren't going to listen to a thing they have to say anymore.  I'll admit, I've done some dumb stuff in my life, but I've also learned from these.  Kids these days, even in high school, need more than the occasional assembly telling us stories about stuff that happens.  Our biggest deal in this county, in my opinion, is marijuana.  It's one of those things that's always going to be around, legal, or not.  Kids have started using other products similar to these, like the insence they sell at some stores or K2, K3, K4, which are more harmful than marijuana, just because our school drug tests them.  These products give off a high that doesn't last nearly as long as that of weed.  Therefore, our students, possibly even our future leaders of this country, are using this product more and more, intensifying the dangers.  I'm not saying that our country should legalize weed, I'm just saying, it'd be a lot more healthy if our school didn't do the drug testing, and if they'd just let us make our own mistakes.
I understand why we drug test, and I'd be willing to take one at this very moment, only because I know I'd pass.  I just believe that what we do in our spare time is none of the school's business. It's not their business what we do when we aren't in their possession.  I do believe however that it is our school's right to know if a student brings such illegal products to school.  Those rules aren't in question.  I'm not saying that PCHS is a bad school, I'm just saying they need to take a step back and realize that they're pushing their students to a much more dangerous fate, because some of the things that are impossible to test for, such as duster, are far more dangerous than that of a simple blunt.