Cycling rule enforcement in NY

As part of the coverage of cycling-city-ideas-from-abroad, here's footage of the New York Police enforcing traffic laws, which apparently includes a requirement to have a bell. Clearly lacking a bell is a punishable offence.

Bristol cyclists do not yet receive such treatment, which must upset some of the people who write letters to the Evening Post on a regular basis. Incidentally, this shows the merits of wearing a helmet. (Source: Gothamist. Very divided comments).
Updated: the New York Times has more detail. Apparently the cyclist was arrested for his part in the incident -for "attempted assault, disorderly conduct and resisting arrest".