Imagine walking back to find a fake meeting invite sent from your unlocked computer... that's more than a joke, it can ruin your week. @nelson.iris is right about small things becoming big headaches. I once saw a coworker accidentally close a report without saving because someone clicked around on their screen. It's not just about sensitive files, it's about wasting time and causing confusion... and IT has to step in when things go wrong. Trusting people is fine, but leaving your screen open is just asking for something to happen.