Your backyard party in New York City this Labor Day weekend could be crashed by an uninvited guest: an NYPD surveillance drone. Officials announced Thursday they would use the aircraft in response to complaints about large gatherings, even including private events. “If a caller states there’s a large crowd, a large party in a backyard, we’re going to be utilizing our assets to go up and go check on the party,” Assistant NYPD Commissioner Kaz Daughtry said at a news conference. Privacy advocates immediately denounced the plan, questioning its legality and whether residents would tolerate such intrusions. “Clearly, flying a drone over a backyard barbecue is a step too far for many New Yorkers,” said Albert Fox Cahn, executive director of the Surveillance Technology Oversight Project (STOP).