Pretty sure you'd draw that line somewhere. Perhaps it wouldn't be a train, but I can assure you with absolute certainty that there would be a point where you would value your lawfully possessed property over an attacker's life.

Anyway, we kind of went off track (no pun intended), but my initial point was that since you can rob these trains with basically no reprecussions, would it still be true if there was a chance that you might get shot in the process? I'd think not.