The accompanying note to the video at YouTube gives you the background you need to frame what you're about to see:
On the night of July 27th, 2012, a huge prank was pulled in New York City and this is the video of what took place. Brett Cohen came up with a crazy idea to fool thousands of pedestrians walking the streets of Times Square into thinking he was a huge celebrity, and it worked! Not only did it work, it caused quite a stir. This social experiment, of sorts, makes a profound statement about how modern culture is so attracted to pop culture, without any real credibility needed.
No real credibility needed.
H/T to Deacon Greg Kandra.