@BryanLunduke while RiseUp might be slightly anti-capitalist, I don't believe that they're pro-violence, etc. Just because Antifa uses RU doesn't mean that RiseUp = Antifa Email.
I find you kinda slathered on the FUD a little too thick in that video. Mozilla wants activists to have a secure place to communicate, RiseUp offers that. Regardless of political leaning or cultural persuasion, RiseUp is open to all activists, no matter how mislead they might be.