Dark Side Of The Net

Are the internet's trolls beyond taming? Twitter, Facebook, and Google sign a European agreement to curb online hate speech. Plus why are huge caches of passwords hacked and stolen many years ago now turning up for sale on the "Dark Web"? And the Brazilian startup using sounds to send data between phones and objects.

Presented by Rory Cellan-Jones, with Zoe Kleinman from the BBC Online tech desk and Joseph Evans, social media specialist at Enders Analysis. (Image: Pointing finger emerging from computer screen, Credit: Thinkstock).