Where an officer makes a Terry stop based on an anonymous tip, that stop is valid only if the contents of the tip provide reasonable suspicion of criminal activity.The 1st District Appellate Court reversed and remanded a decision by Cook County Circuit Judge Thomas M. Davy.On the night of Sept. 15, 2009, Chicago police officer Patrick Kinney and his partner, Richard Antonsen, were on patrol in plainclothes and in an unmarked car when a man they did not know flagged them down.The officers claimed that the man, described as …