The New York Times (registration required) has a fascinating piece on virus fighters, and the ways they work. One of the most illuminating grafs:

combating a major virus quickly becomes a joint effort of all those involved in antivirus research, regardless of their competitive position.

“There’s very fierce competition on the sales side, but on the technical side we share what we have,” he said. “The cooperation and communication is very open among the small group who are doing deep research.” Mr. Hypponen said that in the 1980’s antivirus researchers felt they needed to guard their work for competitive reasons, but they quickly realized that secrecy caused disastrous delays. These days, the roughly 150 researchers around the world know that it is to everyone’s advantage to share code samples and information.

This is a kind of social practice, or a mode of cooperation, that historians and sociologists have describes as a defining feature of Silicon Valley, too. AnnaLee Saxenian, in her classic Regional Advantage, talks about how engineers at competing companies would share equipment when they were having problems.

It was just a throwaway line, and it didn’t sound like people would cooperate in this same way in the course of ordinary work– roughing out specs, coding, etc.– but that people were obliged to help each other under emergencies. The moral economy of the Valley’s engineering culture set rules governing when people who normally would be competitors were obliged to compete. Once again , you have to cooperate with your competitors to survive.

For people trying to combat viruses and worms, every day is an emergency; so it sounds like they’re in a permanent cooperative mode.