A pretty predicament

Last year (2009) in April, right at the end of the semester, Matthew's trusty bicycle was stolen from his apartment. So laamme. So, ever since then, every time we pass a bike rack, Matthew checks if his bike is there. Never is. Almost a year later, we've kinda given up on it (esp since we got another bike since then...). BUT, yesterday night, after Matthew's basketball game, we were walking out of the RB, and just sitting there, calling to us, waiting for us to come, was Matthew's bike. Indubitubly it was. So here's the predicament: It belong(ed?) to Matthew. It got stolen. Now someone else has it, locked up on campus. Maybe they were the ones who stole it, so they would be guilty. Or, maybe they just bought it from the people who stole it, so they would be the innocent victim. We were tempted to get some bolt cutters and take it right then and there... but you come to a sort of fine, gray line where well, it was his bike, but now someone else might think its their bike, so its like we'd be stealing from them. Here's what we did: we got Matthew's bike lock from home, locked up the stolen bike again using his lock, and left a note (that I thought was pretty friendly) saying essentially: "hey this is my bike it got stolen, but lets just talk about it, call me and  I'll unlock it." That was last night. Today, the bike is still there, seemingly untouched. Matthew was thinking that if nothing happened by Friday evening... he might just take a set of bolt cutters to it and claim what should rightfully be his. :)

Ok, I'd like opinions. What do you think is the best thing to do here/what would you do?