I was walking or trotting diagonally across Pennsylvania Ave., at 7th St. against a red light, and had gotten perhaps 1/4 across when a cop suddenly appeared in my path and motioned me back to curb -- after which he invited me to come ahead if I was looking for trouble. Presently he joined me on curb and, though we were far from chummy (standing 6-8 feet apart) we discussed the pedestrian control laws, and I pointed out that a pedestrian should have the privilege of crossing a street, when no traffic was in sight (as was the case with me) against red light.