The Juniper Park Civic Association and the Queens Civic Congress have filed a lawsuit against the NYC Parks Dept. that could result in the abolishing of off-leash privileges in many parks:

Juniper Civic obtains Order to Show Cause against NYC Parks Department for encouraging dog owners to allow their dogs to run off their leashes from 9pm to 9am in violation of the city Health Code. Hearing is set for June 27th in Queens Supreme Court. (–From the JPCA website)

Currently, from 9 PM to 9 AM, city parks that do not have dog runs are not enforcing the leash law and dog owners know this as off-leash hours.
The parkies that walk their dogs without leashes during the off-leash hours are still subject to the law and if any dog seems unruly, a ticket can be issued.

NYCityPets feels the entire issue is one of education. Do park goers really know where and when dogs are allowed off-leash? Many do not and are surprised when they see dogs running loose in the parks. Do park goers know that nighttime off-leash hours help to maintain park safety? If there was a public awareness campaign (with positive spin) to teach people about the off-leash hours, maybe everyone would feel more comfortable. You should know, however, that the JPCA has been barking up a storm about this issue for a while now, unfortunately.

Some large communities have sprung from these off-leash hours. NYCityPets hopes that this tradition will not be lost to bureaucracy. Dog owner groups in Prospect Park, Central Park, Riverside Park, Fort Greene Park, Marine Park, and Juniper Park among others, need to show NYC how much good will comes from a little leash-free dog play.

Here is one opinion on this issue.
Even more interesting is the fact that dog owners near Marine Park are asking the same question as the JPCA: Why do the off-leash privileges only apply to parks without designated dog runs? With a new dog run coming soon, many Marine Parkies would rather keep their off-leash hours instead.