I have spent most of the week poring over news stories, blogs and commentary on last week’s decision by Bay Area Rapid Transit officials to shut off cellphone service to quash planned protests on its trains and platforms.

Opinions are many and range from BART spokesman Linton Johnson, who says constitutional rights end the moment people walk through transit-authority turnstiles, to “X” of the hacker collective Anonymous, who protested BART’s action and said our freedom to connect should be absolute and universal.

I tend to agree with “X,” but adding my criticism to what has already been heaped on BART seems of little consequence at this point.

What does matter is the dangerous precedent set by public agencies that silence new media, and the need for clarity about our free speech rights regardless of the medium.

The San Francisco incident is not unique. Earlier this summer Cleveland’s City Council passed an ordinance outlawing the use of Facebook and other social media to assemble unruly crowds. While a mayoral veto struck down the Cleveland ruling, the overreaction is part of a spreading official backlash against political organizing on new media.

Other governments have responded the same — see China, Burma, Iran, Egypt, Tunisia, Bahrain and beyond. In many instances they simply direct the state-run service provider and cellphone carriers to shut down their networks.

In the U.S., though, companies often flip the kill switch on their own. Verizon Wireless blocked text messages in 2007 that a reproductive rights group sought to send to its members. The carrier decided that the texts were “controversial and unsavory” and implemented a rule buried deep within the company’s terms of service that gives Verizon the power to cut off mobile communications “without prior notice and for any reason or no reason.”

That Verizon reversed its decision after its censorship was exposed by the New York Times should offer little comfort — neither should the notion that fierce public criticism has sufficiently warned BART against switching off mobile communications in the future.

These incidents reveal a growing pattern of abuse and a great measure of confusion over free speech rights in the tangled realm of new media.

“We have free speech rights everywhere. Or at least everywhere in the U.S. when government applies its power,” argues First Amendment scholar Marvin Ammori.

“If the spokesperson for BART reflects BART’s understanding about freedom of speech at stations, then BART’s leadership is wrong,” Ammori says, adding that dismissing the free speech rights of citizens in such a reckless and all-encompassing fashion puts BART on shaky legal ground.

While these are new technologies, this isn’t a new issue. People have sought to speak out using the best means available, whether that’s strapping a note to a pigeon’s leg, handing out printed pamphlets on a street corner or tweeting from the subway.

Governments have routinely sought to shut down technologies that disrupt their authority. But our basic freedoms should remain intact. Whether public and private entities have the right to silence social media and cellphone networks has become a question for the courts.

That’s why the recent uptick in U.S. censorship is cause for real concern — and reason enough for our judicial system to provide clarity on behalf of free speech everywhere.