Peter you've always been a big advocate of talking things out and negotiating before taking action, right?
If you feel that one of your co-worker has wronged you, why not take the issue to you boss or someone else in charge? This way you're on record and thing should be investigated in the "open". You won't have to resort to being a "scum-bucket" and go through someone's personal things.
The American Republic will endure, until politicians realize they can bribe the people with their own money.
- Alexis de Tocqueville
No man’s life, liberty, or property is safe while the legislature is in session.
– Mark Twain (1866)