The hacker group Anonymous is taking on San Francisco’s subway system after the Bay Area Rapid Transit turned off cell phone service in stations last week to foil a protest over a police shooting.

Anonymous, a loosely knit group that has attacked financial and government websites, has called for protesters to descend on the Civic Center station in San Francisco at 5 p.m. on Monday, publicizing the action with tweets from @YourAnonNews.

The transit service shut down cell phone networks in some stations on Thursday to stop demonstrators from organizing a protest over the fatal shooting of a man by police last month.

Lynette Sweet, a BART director, said managers of the system should not have announced the phone network shutdown. In a city known for civil rights protests and technology, that tactic has landed the commuter train system in a new controversy.

Would-be protesters were encouraged to download software for short-range mobile-to-mobile messaging, in case the in-station networks are shut down again.

BART said that a website for its users,, had been hacked over the weekend, and that contact information from at least 2,400 people had been stolen.

(Reporting by Emmett Berg, editing by Anthony Boadle)