Our brains are still running security software designed to protect us against lions, tigers and bears and we haven't run an update for about 200,000 years. Aleks Krotoski explores how well it works when faced with the risks of the digital world.

According David Ropeik author and risk communication expert at Harvard University the modern technological world presents our risk perception abilities with much more complex and abstract problems than it was ever designed to cope with. For him we feel risk rather calculate it so whether its cyber-terrorism or climate change if the risk doesn't immediately push our risk buttons we simply don't know how to react with the risk of getting risk wrong.

And no-where can the risks seem more abstract than in the digital world. Aleks explores how we respond to the dangers that lurk there through a range of stories. We spend time being driven round the Channel island of Jersey in the company of Toni an 18 year old who gives lifts to people she's only ever met through Facebook, we'll hear how a professional online poker player uses the minimal information she can glean about other players to know when to bet big and Aleks will also discover how even a walk in the park can put our technology and the private information we keep there in jeopardy.

Producer: Peter McManus.