AKMA has an eye-opening post about his encounter with a police officer who didn’t want him to use his computer near a library with Wi-Fi access. I’ve seen this sort of thing before, where a cop wants to control someone’s behavior by reference to some arcane law that he only dimly understands (often because the policeman is imaging a law that doesn’t exist).
P.S. If you want a better practice, check out this Ultimate Guide.