It's been 25 years since the first PC virus (Brain A) hit the net, and what was once an annoyance has become a sophisticated tool for crime and espionage. Computer security expert Mikko Hyppönen tells us how we can stop these new viruses from threatening the internet as we know it.

Cybercrime expert Mikko Hypponen talks us through three types of online attack on our privacy and data -- and only two are considered crimes. "Do we blindly trust any future government? Because any right we give away, we give away for good."

Recent events have highlighted, underlined and bolded the fact that the United States is performing blanket surveillance on any foreigner whose data passes through an American entity -- whether they are suspected of wrongdoing or not. This means that, essentially, every international user of the internet is being watched, says Mikko Hypponen. An...