This week, Guardian technology editor Charles Arthur meets CEO and founder of Silent Circle Phil Zimmerman. Phil discusses how he created one of the earliest online email encryption software, PGP, and why his new venture in the app market is proving a popular with security services and businesses around the world.
In her latest Email from America, Aleks Krotoski writes to Yahoo to plead for the survival in it's present form of their most recent purchase, Tumblr.
And we have a tech news round-up, including Apple's tussle with the US senate over their tax affairs and the 'hit and tweet' incident which led to Norwich police tracking down a driver who boasted on Twitter about knocking down a cyclist.
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