Tech Tent 13: "Catastrophic" security bug hits internet

There have been dire warnings over the biggest security flaw to hit the internet in years - what's the right way to protect yourself from so-called Heartbleed? Tech stocks lose all of their gains of the year so far - is the party over? And, the role of tech startups in Rwanda's transformation.

Presented by Rory Cellan-Jones, with special guest Dr Sue Black from the Department of Computer Science, University College London, and Leo Kelion and Dougal Shaw from the BBC Online Technology desk.