When you're a minor at a public school, you forfeit some of your rights. Remember, they still need a warrant or permission to search backpacks and cars. Lockers are school property, so they can open those, they just can't go through your bag. I have a problem with the militant way in which this country's law enforcement deals with drugs, but that's another topic for another time.
"COLONEL KLINK, WHY HAVE YOU FORSAKEN ME?!"