Doug Clarke picked up on this item from Streetsblog:

Revealing statistic:

People riding bicycles — both conventional and electric — are responsible for a vanishing trace of pedestrian fatalities in NYC. Drivers who speed and fail to yield remain the biggest causes of death. Yet the Midtown North precinct, which only issued 37 speeding tickets in the month of February [PDF], confiscated 38 bikes on Wednesday. …

NYPD officers confiscated 247 electric-assist bikes in a 24-hour period on Wednesday, AMNY reports. E-bikes remain illegal under state law even though federal rules have permitted them for years.

The sting appears to be part of a citywide crackdown in the name of traffic safety.