Thousands, or even millions, of people commute to work into our major cities by train. These commuter trains, it seems, would be trivially easy to sabotage (well, to my non-terrorist eyes the tracks would be easy to get jiggy with).
Even if all those people riding the trains were carrying Thompson guns, when the wheels roll off the tracks, the gats are not going to be of much help...
Mark W.
Could happen. But we can't stop that. There's just too much track to guard. Just like we can't guard every bridge and overpass. Even the Hun couldn't do that during WWII and they were much more ruthless and had less to guard.