The Hasids seem astonished by the civvies on bikes, escorted by police cars and scooters.

Welcome to Critical Mass, Brooklyn-style.

This isn't Manhattan's arrest-filled Critical Mass, which had few police problems until 264 arrests were made when some 6,000 cyclists hit Manhattan during the Republican National Convention. Everyone assumed this aggression would end once the chickenhawks left town.

During the next 12 months, however, the NYPD made dozens of arrests at Critical Mass. Bikes were confiscated, tickets issued and bikers and cops engaged in an increasingly complex game of cat and mouse; text messages vs. helicopters. Numerous calls to the NYPD requesting an explanation of the crackdown went unreturned.

To avoid arrest, many cyclists opted to participate in Brooklyn. Here the cops escort cyclists—and there has never been an arrest. Why does the same city have two radically different approaches to Critical Mass? No one seems to know—or, at least, no one is willing to say.

During Manhattan's last Critical Mass, the NYPD suddenly snapped their 13-month arrest streak. Was this a policy change, or just cops lying low because of poor turnout? We won't know until spring wakes the fair-weather activists.

The NYPD may have spoiled that progress by initiating a crackdown on cycling traffic citations (including $60 tickets for riding without a bell or reflectors)—a crackdown the department first denied, and than attributed to numerous complaints about bikes, an unlikely story.