The move was in apparent retaliation for BARTs decision to temporarily to commuters last Thursday in response to a planned protest against the shooting of a homeless man by BART police in March.

News of the attack was released via a associated with Anonymous' attacks on BART. However, another account used by Anonymous for this morning's incident.

"Some random Joe joined a channel and released the data to the press," the tweet noted. Another tweet noted that the leak of BART police data "could be the work sanctioned by those who truly support anonymous, or agent provocateurs. Stay skeptical."

This is the second time in less than a week that hackers claiming to be from Anonymous have attacked BART for the same reason. Earlier this week members of the group and released user names, addresses and phone numbers of more than 2,000 BART customers.

BART did not immediately respond to requests seeking comment on the latest intrusion. But a brief statement posted on BARTs main site condemned the attack.