I have two theft-worthy touring bicycles, but my "worry-meter" no longer is on overdrive, as it was when they were new (1985 and 2004). I take care to secure them, using two locks if conditions warrant, choosing places where people are milling around. My guess is that bike thieves have been tempted, but deterred by chunky locks and a lack of privacy.

I worry (a little) when I am forced to leave my bike in a "bad" part of town, but I have been lucky for the past 26 years. I think a strong U-lock and a chain are effective deterrents.