Under the Espionage Act, certain classified military facilities can't be photographed, but that's it. But if photographing buildings puts you at risk for being hassled, police often take it even more personally if you photograph them at work. As attorney Morgan Manning reported in Popular Mechanics, people who photograph police in the process of arresting — or beating, or shooting — suspected criminals often find themselves confronted by officers who demand that they hand over their cameras or delete the incriminating images.
Again, the police don't have any authority to do that. In fact, the United States Court of Appeals for the First Circuit has held in the case of Glik v. Cuniffe that the right to photograph police officers in public spaces is so clearly established that officers who break the law by interfering with citizens who do so can't plead "good faith" immunity.Good-faith immunity is supposed to protect officers who have to act quickly in areas where the law is unclear. The right to take photographs of police officers in public places, said the Court of Appeals, isn't unclear. (In fact, it's so clear that the Justice Department has written a letter to law enforcement agencies making that point.)
Watch Reason TV's great vid on this very topic: