You could call it a modest victory for civil liberties. A police unit for Bay Area Rapid Transit (BART) briefly shut the Civic Center subway station in San Francisco on Monday evening in response to a demonstration. But, unlike last week, it appears that BART declined to cut off mobile phone access, even as activists briefly held up the departure of an outgoing train.

I happened to be at the station and I could check my Facebook and Google+ pages on my Droid, and could even call home while around me BART police chased protesters up and down the platform. "Protect Free Speech" and "I believe in Free Speech!" declared the protesters' signs as they dodged riot cops. They were objecting to BART's move last Thursday to cut off mobile phone access in some stations in anticipation of a protest over several fatal police shootings on the transit system.

BART claims that it took that controversial step last week because organizers "stated they would use mobile devices to coordinate their disruptive activities and communicate about the location and number of BART Police." Thus BART "temporarily interrupted service at select BART stations as one of many tactics to ensure the safety of everyone on the platform."

A transit official justified the move to CNN more plainly. "We made a gut-wrenching decision that was forced upon us by the protesters," he explained. "They [the activists] made us choose between people's ability to use their mobile phones (and) their constitutional right to get from point A to point B."

The move was "unacceptable," said Jebon Cochran, one of Monday's demonstrators, when I asked him about it. "That's the kind of stuff that happens in places like Egypt, where Mubarak did it to put down the protests, and Tunisia, where the dictator did it to put down protests. That should not be happening here in the United States."

Watch me tweet

But it did happen. No big surprise that BART got a little visit from Anonymous shortly thereafter. The hacker collective broke into various BART-related websites, popped those ubiquitous Guy Fawkes masks onto some pages, and even obtained the names and e-mails of around 2,400 individuals in a BART database, according to BART.

Then came the real-world protest. "People of San Francisco, join us Monday, August 15th at 5pm for a peaceful protest at Civic Center station to illustrate the solidarity with people we once knew and to stand up for your rights and those of your fellow citizens," an Anonymous dispatch declared.

"We request that you bring cameras to record further abuses of power by the police and to legitimize the protest. The media will certainly spin this in an attempt to make our actions appear to be violent or somehow harmful to the citizenry at large. Remember, this is a peaceful protest. Any actions trying to incite violence in our protest are not of our people, and they ought to be discouraged."

Notwithstanding the edgy mood that always accompanies these affairs, the protest was a largely peaceful event. By my guesstimate, 60 demonstrators and an equal number of reporters showed up. I even managed to find someone with a Guy Fawkes mask hanging around. Not surprisingly, he insisted on identifying himself as" Anonymous." We compared notes on the connectivity situation.

"Is your cell phone working?" I asked.

"Oh yes," Mr. Anonymous cheerfully replied. "Many people have taken pictures of me tweeting."

One thing is clear

The tweeting conditions from BART stations may have improved, but BART is still under heavy fire from civil liberties groups like the ACLU and the Electronic Frontier Foundation. The Northern California ACLU put out an action alert regarding the phone access closure on Monday.

"All over the world people are using mobile devices to organize protests against repressive regimes, and we rightly criticize governments that respond by shutting down cell service as anti-democratic and a violation of the right to free speech and assembly," NorCal ACLU Technology Officer Nicole A. Ozer told its members. "Tell BART we are not willing to tolerate silencing of protest here in the United States."

The EFF's statement, titled "BART Pulls a Mubarak in San Francisco," begins by asking a series of pointed questions. For one, did BART cut off access to various mobile phone nodes itself, or did the agency contact carriers and ask them to do the dirty deed?

"One thing is clear, whether it's BART or the cell phone carriers that were responsible for the shut-off, cutting off cell phone service in response to a planned protest is a shameful attack on free speech," the commentary concludes.

Cell phone service has not always been available in BART stations. The advent of reliable service inside of stations is relatively recent. But once BART made the service available, cutting it off in order to prevent the organization of a protest constitutes prior restraint on the free speech rights of every person in the station, whether they're a protestor or a commuter. Freedom of expression is a fundamental human right. Censorship is not okay in Tahrir Square or Trafalgar Square, and it's still not okay in Powell Street Station.

Time to go

About a half hour after it had begun, Monday's BART demonstration started to wrap up. Following a tussle between police and several demonstrators who appeared to be standing between the doors of a BART train, a BART officer positioned himself next to me with a loud bullhorn.

"This is an illegal demonstration," the officer announced. "This is your final warning. The station is closed."

Somehow, with protestors, reporters, and cops still milling around, it was hard to take him seriously. Then I looked up at the station LED schedule screen above the officer's head.

"CLOSED! THIS STATION IS NOW CLOSED!!" it proclaimed. "PLEASE EXIT THE STATION!"

OK. I got it. So did everybody else. "Disband the BART police... no justice; no peace!" the activists triumphantly chanted as they queued up the back escalator and marched into the street.

"All BART Stations are Now Open, Trains Running On Time," the service declared shortly thereafter.