Thanks NanKate, for starting this thread. What can we GNs actually do? Well, someone said it was his birthday soon, so, taking a leaf out of the Amnesty International 'playbook', we could send him a card. Yes, it sounds naive. And no, I don't think any/many of our cards would get as far as Navalny himself, but they will get somewhere along the line. They will show that the world has not forgotten him, especially as GNs are from all over.
Practical point, do we send them to the Embassy in London/your own Capital, if it is still functioning, asking them to send it on? Do we send them to his family, to show our support?
Having a busy-ish Boxing Day here, but will be back on this thread later, and looking forward to your helpful suggestions.