DIASPORA*, in case you don't remember, is the free software alternative to Facebook, consisting of a number of connected but independent servers -- or "hubs" in DIASPORA*-speak. Although less than a year old, the project has already received considerable attention -- first because, in the tradition of the great IT myth, it was conceived by a group of college students, and, second, because it raised one of the largest total of donations ever on Kickstarter. A few months ago, there were also considerable complaints about the lack of security in the pre-alpha release.
I can't speak about the code. However, judging by the privacy pollicy and the interface, DIASPORA* now appear to be taking security more seriously.
rest here