Long time ago, in Dallas, I lived in a not so nice neighborhood and locked my bike to a tree, with heavy chain, right outside my front door. One day I came out and found my bike gone. The chain was still there, as was the lock, locked securely to the chain. It seems that the local tow truck companies had a license to steal. Anything they found illegally parked, they could tow. Cost me $67 to get my bike back.