Delivery bike riders seem to me to be totally out of control here in Brooklyn, riding the wrong way, ignoring red lights (perhaps what happened here) and doing both at intersections as they turn going up another wrong way street. They're just about as dangerous as cars, especially because they're always in a hurry while riding recklessly.
Here's the bike helmet law going into effect for delivery people for NYS:
http://open.nysenate.gov/legislation/bill/A6741-2011