You want to cut off the internet? Fine. You can't stop us from communicating, though.
Although if there was an agent with a phone in the area, he could see what everyone was saying, even if not who was saying it.
[0] https://en.m.wikipedia.org/wiki/2013_protests_in_Turkey
[1] People started using VPN's and most people knows what DNS is now. So, there is hope.
Years ago we would have said the same thing about internet access. 'How could the internet (or mobile data) help in emergency or oppression situations ? Only geeks would have such a thing. ' (1990s)