There are more than 280 million cellphone subscribers in the U.S., and many of those phones can record video. With so many cameras in pockets and purses, clashes between police and would-be videographers may be inevitable. All of us, as we walk around, have to understand that we could be filmed, we could be taped," says Deborah Jacobs, director of the ACLU chapter. "But police officers above all others should be subject to this kind of filming because we have a duty to hold them accountable as powerful public servants." Tom Nolan, a former Boston police officer, says police have to get used to the world of cameras everywhere. "There's always going to be a pocket of police officers who are resistant to change," he says. Nolan now teaches at Boston University. He says police in Massachusetts train their officers to tolerate video recording, as long as no other crime is taking place. And Nolan thinks departments around the country will eventually do the same. "The police will get the message when municipal governments and police departments have got to write out substantial settlement checks," he says. "Standing by itself, that video camera in the hands of some teenager is not going to constitute sufficient grounds for a lawful arrest."