Microsoft's former chief privacy adviser says he does not have faith in the security of the software company's technology, following revelations about the US's NSA spy agency published in the Guardian.

Caspar Bowden, who between 2002 and 2011 was in charge of the privacy policy for 40 countries in which Microsoft operated but not the US told a conference in Lausanne, Switzerland, that he was unaware of the Prism data-sharing program when he worked at the company.



"I don't trust Microsoft now," he said, adding that he only uses open source software where he can examine the underlying code. He also said he has not carried a mobile phone for two years.