Found this comment as a response to the 9/11/11 detention of a woman that was sitting on a plane next to men that used the bathroom too much. It doesn't have anything to do with RR photography but the circumstances are the same--taking photos from a roadway and getting hassled and threatened. The quote:

"As an amateur photographer, I was detained post 2003 because some off duty cop, fresh out of "Terrorism Training" reported me for being near a public roadway. Never identifying himself as a police officer, the man attempted to detain and restrain me until a uniformed officer in a patrol car arrived. The uniformed officer privately admitted that the other person was over-reacting. None the less, my information was taken and assumingly entered into Dick Cheney's secret database. "Thanks" to that fat off-duty SOB and his equally fat wife for the illegal searchin and seizure.

I was warned "not to take photographs near a public right of way in the future or further action would be taken". Say 'what'? Welcome to the New World and the New Millenium- I guess... sheesh!"