I was doing a bridal photo shoot in D.C. at the Lincoln Memorial and ended up with a crowd of half a dozen or so tourists (mostly foreign folks just interested in the "American bride") following us around with still and video cameras. Fortunately, the bride was a D.C. local and used to the tourists thing, so it didn't bug her out. But in order to shoot in public, we had to apply (and pay) for a permit from the parks department.
Same thing in NYC. If you are a professional photographer, you're required to get a permit to shoot on the the street. The funny part is, in NYC and D.C. alike, the "permitted" photographer is limited by a huge set of rules, etc. of what you can/can't do, etc. and the number one rule is, you cannot interfere, impede, annoy, etc. any tourists, locals, etc. by your actions. Basically, John Q. Public can photograph anywhere and anything he wants, but a pro is held to a higher standard.
Personally, I think the "pro's" setup looked pretty lame, and the mother or whoever should have totally expected, let alone anticipated, that a crowd would gather and be taking their own photos/video, etc. But if that's the weirdest, wildest, sexiest thing that guy could find in Times Square to video, he wasn't trying very hard.