The World of Wiki

Have we seen the world's biggest hack attack? Over one billion usernames and passwords have reportedly been stolen by a Russian gang. But how serious is this attack? Security experts will be discussing the fallout with us.

Wikimania is the largest event of its type for those interested in wikis and open content. What actually goes on and what is being discussed this year? Jimmy Wales, the co-founder of the wiki world's most well known product Wikipedia, will be giving us his views on that and the organisation's new transparency policy. He'll also be telling us how Wikipedia deals with "right to be forgotten requests".

How has one man convinced 25,000 people to join him in a lawsuit against Facebook over privacy? And why does he feel so strongly about it? Max Schrems explains why he's ready for his day in court.

The great and the good of the hacking world have descended on Las Vegas for the biggest underground hacking conference of its kind. Defcon takes place in Las Vegas and BBC tech reporter Dave Lee is there. He tells us what are the big news items in the world of code cracking.

Presented by Rory Cellan-Jones and featuring Zoe Kleinman and Leo Kelion from the BBC's online technology desk.