Veronique4, thank you very much for doing what you can to improve the bike path, and also for your eye-opening grace in the face of what looked to me like snotty, holier-than-thou insensitivity. I couldn't have done it, but it cheers me up to see you do it!

Whether or not the thefts were actually illegal, I suspect the police have bigger fish to fry, and by posting your signs you've exhausted your remedies outside of the law. But if you want to put forth the effort to get a photo of the thief, I wouldn't be surprised if the thief turned out to be someone who steals other stuff too, so it might be useful to the cops whether or not those particular thefts were actually technically against the law.