BART officials acknowledged this afternoon that they shut down cell phone and wireless data service in its downtown San Francisco stations to disrupt a planned protest. Their announcement sparked denunciations from civil libertarians and the apparent threat of a cyber-attack on the BART website. A statement posted on the transit agency's website said the communications blackout was ordered in the interest of public safety: "Organizers planning to disrupt BART service on August 11, 2011 stated they would use mobile devices to coordinate their disruptive activities and communicate about the location and number of BART Police," the statement reads. "A civil...