This morning, Andrew Sullivan linked to an ABC article about civilians who have been arrested for capturing video or audio recordings of on-duty police officers. Many discussions of this subject — including the article mentioned above — frame citizens' rights to tape police officers in terms of First Amendment rights, but I'm not sure I agree.
To me, this is an issue of Second Amendment rights. If the Second Amendment is meant to arm citizens with the tools necessary to protect themselves against encroaching state power, I think that cell phone cameras and YouTube are the muskets of the 21st century. No modern civilian or group of civilians, no matter how well-armed with guns or bombs, has any prayer of fighting off the police (or army) by force. If police officers or soldiers are abusing their power, the best weapon of self-defense available to the modern American is media exposure.