Smartphones are making it easier than ever for people to record police encounters with the public, providing evidence of beatings and shootings that wouldn't have existed otherwise.

But some police departments are responding to the scrutiny by arresting citizen videographers on such charges as obstruction or interfering with a crime scene. And even though recording police is protected by the First Amendment, civil libertarians say such arrests are only becoming more frequent.

New York's ACLU has been fighting back with an app that automatically uploads citizen videos to a central server, preserving them even if the smartphone is seized.

And California Gov. Jerry Brown recently signed a "Right to Record Act" that specifically declares people may not be prevented from recording the police.