OK, as a photo/videographer myself, I have been in Chris' shoes many times before. The most recent was in Philly's airport awaiting to fly home. I was waiting at the bumper at the end of the track when a cop showed up and told me the same thing we have all heard before...9-11...blah-blah-blah. I just stood my ground and continued photographing.
A few days prior to that I was at Union Station in DC...same thing. This time I had just detrained from the Acela when two thugs came up to me and told me that I couldn't take photos of the train. I told them that Amtrak has a policy that I could, however they both told me that they hadn't heard of it (likely story). They left me alone...for a few minutes then saw me taking photos again of the same train. They advised me that if they caught me taking photos again they would have me arrested.
My next move was to go to the stations management office and speak with them about the incident. I spoke with a nice woman there who I inquired about the photography 'rules' at the station. She told me that as long as I was not using any tripod or impeding the flow of passengers, she had no issue with me there. She was even kind enough to give me her business card with her cell number on it. She then advised me that if anyone gave me grief for being there, show them my card and tell them to call her directly.
I thanked her and then went back out to try to photograph my train...when you guess it, the two nice officers showed up. They warned me again, but this time I produced the business card. They took a quick look at it, and surprisingly just moved on without saying another word. Amazing.
A while back I was in Puyallup WA, same thing. A 'sekurity' guard approached a friend and myself indicating that we couldn't take photos of the passing BNSF train. He said "Haven't you heard about nine-eleven"? I replied "Yes, that is the number you call if your house is on fire". Again, he just kept walking and never bothered us.
One more comment. Traveling to Europe several times and videoed and still photographed my journeys to no end, I have only been approached once asking what I was doing. And of all people the station agent. After explaining what I was doing he proceeded to tell me a little history about the station, it's trains, and his time there. As much as I love this country of mine, the security folks here could take a little example from the folks across the pond on how to treat railroad enthusiasts. For a nice look at a friends page on a little incident that took place at LAUS :
*click here* Metrolink Welcoming Committee
To sum up, Kudos to Chris for his professionalism, demeanor, and control. And for those others out there who have posted here and other places, thinking that just showing your ID would have calmed the situation down to the point where the police would have just said "have a nice day" and left, no chance in hell. Chris was well within his rights to do what he did, and knew them quite well.