After listening to the You Tube commentary, I get the sense people commenting above haven't done the same thing. The amateur photographer was, IMO, clearly out of line. This character was not a person taking just several photos or a short video, he was was following commuters and Amtrak employees for more than an hour and a half taking photos of them without their permission and when asked to stop he didn't. I would have objected, too, if he was following me - on public or private property - taking and taking my picture repeatedly. Aside from security concerns, there's the concern for our personal privacy - and the right of a private property owner - the terminal owner - to enforce certain policies regarding such photo taking. It sounds to me as if the Amtrak and police employees acted responsibly and with restraint. If you're going to criticize a group for taking action, make certain you understand what happened in the first place.
