I thought his point was that GCHQ doesn’t need to break any encryption, they can just create an account, log onto the groups, and sit there taking notes.
Yeah, that’s what I meant. Lots of people seem to think they are hidden, as they are arranging all their meet-ups on Telegram. But anybody can join those groups, nobody checks who you are. Journalists at The Times are members of some of them and are highlighting the plans for this evening, for example.
Guess the only more difficult bit is linking the online account with a real person.
I see the Birmingham pub has thanked the representatives from the Mosque for their apologies and offer to pay for the broken windows.