In BART's case, the agency has been targeted for temporarily shutting down cell phone service at several stations last week. BART officials claimed that the move was necessary to preserve public safety after several protestors planned a demonstration to protest the killing of Charles Hill by BART police.

Though BART has stoutly defended its action, it has been roundly slammed by civil rights groups for its decision. The

The continuing attacks by Anonymous are sure to increase pressure on law enforcement to track down members of the group. In July, the FBI arrested 14 alleged members of Anonymous for their supposed role in launching a series of distributed denial of service attacks PayPal last December. Similar arrests have been made in other countries as well.

So far, those actions appear to have done little to slow down the attacks. In fact, soon after the arrests, members of Anonymous and LulzSec, a splinter group, issued a joint statement vowing to carry on the attacks and daring law enforcement to catch them.

Jaikumar Vijayan covers data security and privacy issues, financial services security and e-voting for Computerworld. Follow Jaikumar on Twitter at or subscribe to . His e-mail address is .