We were passing from the Picadilly Underground Station south toward Leicester Square, down a wide pedestrian thoroughfare. It was packed with people. Suddenly, we heard fireworks going off, in the middle of this throng of pedestrians. People began screaming and sprinting for cover. Several more rounds were launched -- some sort of bottle rockets sending bright arcs just over hundreds of heads.
We picked up our pace, trying to get out of the area. We had to stop at a crosswalk, and as we stood there, from inside the McDonald's across the street, three or four minutes after the first rocket had gone off -- hey, they had to finish their Big Macs! -- about seven or eight cops raced into the street. Well, not so much raced, as kind of strolled, at a very leisurely pace. They seemed to have no interest whatsoever in finding out who was shooting bottle rockets in the crowd. In fact, they came to a stop about fifteen feet from the entrance to McDonald's, and just stood together in a clump.
My friend explained, "Well, no one was attacking them!"