Once again, police have shut down the location filming of a scene in which actors employed prop guns. Real-life NYPD cops were called to the site of the production of an episode of the CBS crime drama Person of Interest after residents saw the actors with guns and assumed they were real, according to a report on the gossip website TMZ. Officials later confirmed that the shooting permit required that NYPD supervisors be on the set and that the permit was revoked when it was discovered that they were not. In 2011, San Francisco police, responding to a 911 call, overpowered a man wearing a ski mask and brandishing a gun at a market only to discover that he was an actor being filmed by a Japanese crew across the street. A few days later a British film director was arrested after neighbors saw guns being brandished in the backyard of a home in Bristol that was being used as the set of a movie. During the filming of World War Z in Hungary, police confiscated weapons that were intended for use during exterior scenes. And only last month in Oakland, the filming of a fake robbery in which a prop AR15 was being employed was interrupted by police who had received a 911 call. Police said that when one of the actors failed to drop the phony weapon, he was nearly shot.