Bruce Schneier explains why the Witty worm is important in a piece for Computerworld. Witty affected users of an unpatched version of a specific firewall product, and nailed every one of them in 45 minutes. According to Schneier, the worm is small, well-written, and bug free. It’s worth remembering that the only thing that saves most people’s computers from utter destruction is that most worms are written by incompetent programmers. We can all hope that Witty is an anomaly rather than the start of a trend.