You’ll need Faraday bags for your phones when you meet up.
“...and follows the disorganized militias from there to Boston, where 20,000 militia laid siege to the city and the British troops occupying Boston.”
https://davekopel.org/2A/LawRev/american-revolution-against-british-gun-control.html
Above is an article with regard to “The Powder Alarm” which happened on September 1, 1774. Those 20,000 militia started marching towards Boston but didn’t make it that far as news that no actual fighting had taken place. However, the British had seized hundreds of barrels of the local militia’s black powder.
Concord and Lexington was the following spring, April 19, 1775. Some speculate that if the British hadn’t taken the powder, the militia would have been victorious at Bunker Hill.
Perhaps we should adapt and learn?
The Seven Years War, which ended in 1763 (and resulted in the Proclamation Line), was really the first "World War." It was fought on every continent.
Even using a service like Proton Mail, or using local encryption like 256 AES layered with 256 TwoFish although very secure, has inherent weaknesses. Any computer that is connected to the internet at all in any way, has weaknesses that can be attacked.
It is relatively safe as long as that connected computer is not identified as one that requires attention from the all seeing eye. Once that happens, key loggers, root kits, and even physical surveillance can overcome the best encryption and protection techniques.
And that is as it always has been. Passing information requires anonymous participants who are not and cannot be identified. Being online goes a long way to voiding that anonymity when faced with super computers and advanced AI searching for exactly those people.