According to the Contra Costa Times, BART could interrupt mobile phone service on its platform if there is "strong evidence of imminent, unlawful activity" that threatens the safety of passengers or BART employees, or causes potential disruption to train services.
BART officials say those circumstances could include a hostage situation or a situation where a cell phone could be used to detonate an explosive device.
BART had initially defended its position to cut off cell phone service ahead of a planned Aug. 11 demonstration organized online. BART spokesperson Linton Johnson asserted the BART platform -- where, BART claims, protests are not permitted -- is not a 'free speech' zone.
"There was a Supreme Court ruling that allowed, under very narrow circumstances -- you have to meet a lot of tests in order to put public safety ahead of free speech, but there are exceptions," Johnson said.
The Aug. 11 protest failed to organize, but other protests formed following the news that BART had severed cell phone service.