Consider, however, that the law in theory differs very much from its practice. In a Terry stop, just like most encounters with the police, the officer holds all the cards. Non-compliance can be met with force, and there's always the threat of being charged for obstruction or whatever else the policeman thinks up, based on their word alone(which has more weight than yours in court). Policemen are given a wide latitude to act, and a good faith presumption to all their actions, so they can get away with stretching any applicable law to its breaking point.