This is the first time I've ever heard of something called the Critical Mass bike ride, but apparently it is a monthly celebration of cyclists over car drivers and goes through major US cities.
It all sounds horribly irritating to me as a pedestrian. Clearly when it went through Times Square in New York on July 25th it upset another pedestrian too. Only problem looks to be the uniform he was wearing whilst he was walking.
Note: This post is laced with deliberate sarcasm
Update: The officer in question has had his badge taken away. Meanwhile the NY Post thinks there is more to the story than what the video appears to show.