Kids seem to be so naïve when it comes to the web. If anything at all pops up, they just click on it, especially if it says it's going to increase the performance of their PC or let them download something for free etc etc, and that's usually how most viruses manage to get on their computers.
Having said that, I work mostly with academics, professors and post-doctoral researchers etc and most of them don't seem to be nearly as clever as you'd expect when it comes to computers and the web.
Iain.