Episode 1

The internet is used by around 2.3 billion strangers all over the world.

These include rivals and deadly enemies who suddenly find they have the power to cause all kinds of mischief.

Soon, even these may be just a small part of the cyberspace population, as billions of machines and household appliances come online too.

Ed Butler assesses the ever-increasing threats in cyberspace from hackers and cyber weapons, and what can be done to protect internet users.