I looked up my state's statute and interestingly, it states refusal to identify one's self as suspicious and therefore adequate reason to detain. Wow, talk about a self-protecting clause.
(b) Among the circumstances which may be considered in determining whether alarm is warranted is the fact that the person takes flight upon the appearance of a law enforcement officer, *******refuses to identify himself******, or manifestly endeavors to conceal himself or any object. Unless flight by the person or other circumstances make it impracticable, a law enforcement officer shall, prior to any arrest for an offense under this Code section, afford the person an opportunity to dispel any alarm or immediate concern which would otherwise be warranted by requesting the person to identify himself and explain his presence and conduct. No person shall be convicted of an offense under this Code section if the law enforcement officer failed to comply with the foregoing procedure or if it appears at trial that the explanation given by the person was true and would have dispelled the alarm or immediate concern.