It says so here.
SF cell shutdown: Safety issue, or hint of Orwell?
First I don't disagree with what they did. The Federal Government has made it illegal to "jam" cellular signals. I think it should be illegal to intentionally shut down a underground radio system such as this. What if there was an accident or someone had a heart attack.
But if the repeater system wasn't installed to begin with then there wouldn't be cell coverage to begin with. WE the people own the spectrum. It's a public right to use it...so if it's illegal to jam it then it should be illegal to shut this down purposely. And it should be against the law to demonstrate in a public enclosed space.. Then this would never have happened in the first place.
(For those that don't understand how this works...antennas outside send the signal inside via cables to a amplifier and antennas underground. That's how your cell phone works in a tunnel. It's just a relay to the outside world)
I did find it amusing though that these people think it's a civil right.