In Amazon, if security saw you left your computer unattended, they would send an email from your account to everyone on your team promising to bring in cookies / doughnuts / coffee or the next day. The idea being you’d be obliged to carry through and everyone would know you f’d up and didn’t lock your computer.
I still lock my computer when I leave it, even though I work from home. Think it was pretty effective. I wouldn’t screw with their computer language etc as it could hinder their productivity if they’re in the middle of something important.