What I find strange about the article is how it seems to talk mainly about webapps (do not count on Facebook respecting your privacy) but takes Ubuntu as an example. I think it is perfectly fine to use MS Office installed on Mac OSX to write secret letters. Just maybe encrypt the files before sending them via email. I don't quite see the point of using Ubuntu and LibreOffice instead from a security standpoint.
That said, it makes sense that the encryption software should not be proprietary and closed source.