The act of taking pictures mostly causes people to become reasonable fairly quickly. At first this gentleman refused to identify himself. He was pointed out to me as the location manager and finally said he was Tom Hogan from CBS Studios.
The undercroft was in use, according to several people on the premises, as a classroom for children featured in the production:
Here are people leaving the undercroft:
Although several people tried to say they were just filming on the sidewalk, the entire premises were clearly in use:
I've referred this matter to the vestry.
UPDATE: I'm told that a shoot of this size would net the squatters at most about $1000. That won't be enough to pay their bills.