Muslims say NYPD actions have violated their rights and caused injuries.
The judges at the Tuesday hearing in the US Court of Appeals for the 3rd Circuit said that the decline in attendees at mosques, reported by the plaintiffs, is a "concrete injury" since it leads to the loss of money.
The judges did not rule on the appeal Tuesday, however, the plaintiffs and their lawyers said they hoped that the ruling of US District Judge William Martini, who had dismissed their lawsuit against NYPD, would be overturned.
The eight Muslim plaintiffs filed their lawsuit against NYPD in 2012, accusing the police of having spied on ordinary people at mosques in New Jersey since 2002.
The Associated Press has reported that NYPD had crossed the Hudson River to take pictures and eavesdrop on conversations inside businesses owned or frequented by Newark Muslims.
