If a kid is doing drugs, whether that child is doing it in or out of school, the school should be involved if that child shows up under the influence. If a kid is high or inebriated in school it is not only affecting the kid doing the drugs, it is affecting every other student in the class and the teacher. Parents and teachers both play key roles in the development of children and therefore are somewhat responsible for their well being. If that responsibility comes in the form of making them face the consequences of their actions, then so be it. On the subject of it being a breach of privacy, you must remember that as soon as that student enters a school, they lose their rights to privacy until they get home. At school if a teacher says jump, the student says how high (this is just an example of course) and this means that if they want to search your locker or backpack for drugs then they have all the right in the world to do it. This is because if you have something that is illegal or dangerous with you during the school day, this could affect other students and it is the school's responsibility to ensure the safety of the students.
If they are using drugs they are breaking the law, and that is supposed to be private? I see the con, but in the end it is hiding from the law. Drugs kill, and do you want our future to be killed just because we didn't stop them from getting addicted?
I believe random testing for drugs in high school is a severe breach of privacy on the part of the school system. The school system should be held accountable for teaching and stop trying to control their students both in and out of the classroom. If a student uses drugs, that's something the parents should handle and know about, not the school.
I can understand why a school would be worried about a student's drug use while they are on school grounds, however, the school can not have any control of what the student does off of school grounds. The student is then the parent's responsibility until they come back to school grounds the next time. Random drug testing at school doesn't make any sense, it should be the parent's responsibility to keep a close watch on their children. If they suspect there is a problem, they should do the testing.