By “dumbest crime”, do you mean dumbest perpetrator of a crime, or dumbest example of something that legislators in their infinite wisdom have criminalized?
I was in a buffet once that had a sign saying “state law requires diners to take a clean plate each trip to the buffet”. I saw a guy refill his dirty plate, and I called the TIPS hotline to report it, but the police did not seem interested. I suspect that in actual fac,t he state law only requires the restaurant to post tht sign.