I had a doctor's appointment this morning, so I commuted into the city at an odd hour. On the uptown E train (World Trade Center line) at around 11:15, was a man wearing blue jeans, a windbreaker, and a winter cap.

He was carrying with him a hacksaw, a screwdriver, and a flashlight. He didn't have any kind of bag or case, he was just carrying them loose in his hands. I assume he was in a construction-related line of work, and was just bringing his tools to/from his job.

So, I ask again, exactly what are they checking for when they randomly inspect our bags on the subway? If an openly visible hacksaw is OK, what exactly is not OK?