Does anyone find it slightly odd that Snowden was (quite obviously) joining the presentation over a Google hangout? I suppose it's better than a Skype call, but shouldn't he know better? I would expect him to insist on using Jitsi or something similar, like Jacob Appelbaum does for his appearances.
He explained that once in an interview - basically, for public communication, there is no reason for him to care, so he uses whatever suits the other party the best.
I helped set the presentation up. Jitsi is actually the ideal choice, but it's too unstable for something like this. Google Hangouts was used at Snowden's request.