This started happening in my high school a few years ago, Everyone seems to think that they did it to make it easier to catch people doing weed by closing half of the bathrooms at any given time. It’s super annoying because the bathroom closest to my classes are always the ones to be locked for some reason so I have to walk across the entire school (the school is really big) to get to an open bathroom and when I do get there it’s usually so dirty and crowded that it’s almost unusable.