Not your comment, I understand. But you find it logical. So explain the logic.
Typically trains go through right through stations, but that isn’t the exclusive rule. At the end of lines, and places where line spurs head off in different directions, trains can and do wind up in stations where they can in fact run into buildings. The poster could just as easily have talked about running trains off the tracks causing severe disasters. He didn’t, but we haven’t had train become terrorist targets here yet.
The point is, we don’t need a federal police force. The FBI has traditionally carried out that role when there needed to be an investigation carried out over state lines. There is absolutely no need to go beyond that.
I still say, we should eliminate clear threats, and leave the general public alone.