This. Don't put up with their ****. Confront them personally and tell them to shape up or ship out. There's no excuse for what they're doing, and if they don't listen, tell them to find somewhere else to live. That's ****ing disgraceful, putting your house and belongings at risk like that. Of course, if it's not your home and you're all entitled to sharing the place, get personal locks for your own door and keep all your valuables safe. With how stupid they're being, someone's bound to break in sooner or later, and tehy'll only have themselves to blame for anything that happens.