The hacking group got into the website for Bay Area Rapid Transit and stole and exposed personal information on 2400 of the site's 55,000 users. Anonymous was angered by BART's shut down of phone coverage during a protest last month.
The San Jose Mercury News tells of how Anonymous announced the hack:
"You have angered Anonymous," said the video message, which was directed at BART. A computerized voice relayed the two-minute message backed by a dramatic musical soundtrack.
The group also instructed protesters to inundate the work and personal email inboxes of several dozen officials from BART and other agencies.
"This is a Black fax and email Bomb action, the goal being to explode their inboxes," the website said. And the hackers also broke into the website of a police anti-DUI website, California Avoid, and superimposed a masquerade mask over the face of a highway patrol officer.
The paper also quotes a BART user:
"I think that's completely inappropriate," said Livermore resident Annamarie Hastings, one of the people whose information was posted online. "It doesn't make me any more sympathetic to their cause."