"Law enforcement, given a chance, goes hog-wild," my wife Nancy said. She was talking about one of the consequences of the explosions at the end of the Boston Marathon on April 15. By Friday that week, with the City on a Hill in "lockdown," photos of black-clad, half-masked, rifle-ready men flooded the Internet.

"Police SWAT teams, sharpshooters and FBI agents descend on an area stretching from Watertown to Cambridge, surrounding buildings," MSN put it. "Police helicopters buzz overhead and armored vehicles rumble through the streets."

I didn't see them at the time, but NPR's "What It Looked Like From Inside Boston's Lockdown," for example, surely showed some tanklike things. I wonder if Bostonians knew their police had militarized to such an extent.