Police Presence in NYC

I take the 1/9 from 125th almost every day. Since the London bombings, there have been at least three uniformed cops just hanging out by the turnstiles, as opposed to the occasional one or two patrolmen before. They're always there now; they look bored. I saw them talking down a crazy guy a couple of days ago. I haven't seen any bags searched.

This isn't a transfer station, and it isn't near any terrorist targets that I can imagine. (Maybe terrorists have an intense hatred for meat-packers, college students, and subsidized-housing dwellers, but still.) I haven't seen as many cops at other stops on the line.

So is this just a convergeance of the higher police presence in Harlem generally with the stepped-up police presence in NYC after 7-7? What are other NYC residents experiencing?