I had another strange encounter with the Mitzvah Tanks today.

I'd gone to the Central Library to drop off some books (and pick up another Ayelet Waldman novel). When I came out, a whole squadron of their camper-vans were circling the Soldiers and Sailors Arch on Grand Army Plaza, blocking traffic in every direction. About five police cars were in the stew, too, their lights flashing, and a couple of helicopters flew overhead. There was a general feeling of honking, yelling mayhem, and once again I beheld the Mitzvah Tanks with trepidation. I'm telling you there's something about them that makes me nervous. Why "tanks"? Why back up traffic? Why the helicopters? What goes on here?