Officials with the Bay Area Rapid Transit system, better known as BART, turned off electricity to cellular towers in four stations from 4 p.m. to 7 p.m. Thursday.
Apparently, demonstrators were planning to use mobile devices to coordinate the protest.
The tactic drew comparisons to those used by the former president of Egypt to squelch protests demanding an end to his authoritarian rule. Authorities there cut Internet and cellphone services in the country for days earlier this year.
"BART officials are showing themselves to be of a mind with the former president of Egypt, Hosni Mubarak," the Electronic Frontier Foundation said on its website.
The American Civil Liberties Union criticized the tactic, saying on its blog that it was the "wrong response to political protests."
BART officials said in a statement that demonstrations aren't allowed on trains or platforms and that it has set aside special areas for demonstrations.
The demonstration planned Thursday failed to develop. "We had a commute that was safe and without disruption," said BART spokesman Jim Allison.
The demonstrators were protesting the July 3 shooting of Charles Blair Hill by BART police, who claimed Hill came at them with a knife. Several people were arrested when a July 11 demonstration disrupted service during the rush-hour commute and prompted the closing of BART's Civic Center station.
The Associated Press contributed to this report.