I watched the backpack searchers at Penn Station yesterday for about 10 minutes while waiting for my train. I'm keeping tallies of how many people they're stopping and noting their physical descriptions. I hesitate to share details just yet, as I want to watch this in action for the next few days, but I will share this: The only search station I saw was on the main concourse, covering one entrance, which was the entranceway to the LIRR coming off the escalators at the entrance under Madison Square Garden. There is plenty of opportunity for someone to avoid this station if they wanted to, simply by coming in through one of the many other entrances like the one at 34th Street and 7th Avenue, from the subway or from any of the other entrances feeding into the other concourses. Perhaps these are only spot checks, because they're certainly not comprehensive. I'll post an update after I've had a chance to observe searches in action over the next few days.