A series of high-profile hacks and a live protest that shut down San Francisco subway stations has wounded BART, but its foes aren't ready to quit fighting.

Anonymous has BART clearly in its sights and is currently organizing a second live protest scheduled for Aug. 22 at San Francisco's Civic Center station. About 100 or more protesters gathered at the same BART and Muni station this past Monday, forcing BART authorities and the SFPD to for several hours.

The @OpBART Twitter account, a focal point of the ongoing action against Bay Area Rapid Transit (BART) authorities, has been issuing a series of tweets urging people to show up for a protest next Monday at 5 p.m. PT.

BART has come under fire from free speech advocates and drawn the ire of the loose collective of online hackers and activists known as Anonymous for during a protest last Friday over the shooting death of 45-year-old Charles Blair Hill by BART police in July.

Though BART officials first claimed they had asked private wireless service providers to shut down cell phone service during last week's protest, they later admitted that they themselves disabled the underground wireless network the transit agency privately owns and operates, according to reports.

The transit authority has claimed it shut down cell service for public safety reasons, attempting to prevent protest organizers from communicating and organizing via mobile devices in the face of disruptive and potentially dangerous gatherings at San Francisco underground stations.

But critics of the cell service shutdown say BART lacks the authority to cut off such communications and they have attacked the legal rationale espoused by BART spokespeople for doing so, while comparing the transit agency's actions to communications blackouts instituted by authoritarian governments in Egypt and Syria.

BART's chief spokesman Linton Johnson said this week that it was his idea to cut cell service during Friday's protestpossibly the first time a U.S. governmental agency has so brazenly taken such an action to hinder the communications of protesting citizens.

The ongoing operation against BART has drawn support from hacktivists associated with Anonymous, civil libertarians, and Bay Area residents upset with July's shooting and the killing of Oscar Grant by BART police officer Johannes Mehserle on Jan. 1, 2009.

The person or persons behind @OpBART speculated Wednesday that more protesters could turn up for the second protest, given a longer lead time for the rally and more media coverage of the Anonymous operation against BART.

Ironically, while @OpBART has declared its opposition to publishing personal information from hacked websites, there's little doubt that a pair of high-profile hacks of BART-associated sites has generated that extra media attention.

Last Sunday, hackers , defacing some pages and posting mybart.org user data online. On Wednesday, private data belonging to more than 100 BART police officers obtained from a hack of the BART Police Officers Association website was published, with a self-proclaimed first-time hacker .