If you're doing any kind of radical political work --- left or right --- and are worried about the attention you're going to attract, don't use things like RISEUP.NET. You shouldn't be running mailing lists at all. You shouldn't be using Jabber and asking all your peers to enable encryption. These are fundamentally unsafe services, and the idea that they can be provided safely just by paying attention to network security is terribly misleading.
In the universe of possible media in which to conduct discussions with a group of peers, there may be none less safe than SMTP email mailing lists. Keep secrets off mailing lists. Never use mailing lists for secrets. Assume your mailing lists are public. Nobody is going to deploy a mailing list security solution that will ever be adequate against state-level adversaries. Any site claiming to keep political activists secure that offers mailing lists should be viewed with suspicion, because "don't use mailing lists" is close to the only thing that messaging security people agree about.
In the universe of possible media in which to conduct discussions with a group of peers, there may be none less safe than SMTP email mailing lists. Keep secrets off mailing lists. Never use mailing lists for secrets. Assume your mailing lists are public. Nobody is going to deploy a mailing list security solution that will ever be adequate against state-level adversaries. Any site claiming to keep political activists secure that offers mailing lists should be viewed with suspicion, because "don't use mailing lists" is close to the only thing that messaging security people agree about.