THERE IS a new kind of threat gathering online.
Until now, the story of the Internet wars has been a tale of escalating software. Shadowy criminals (or bored teenagers) design code which infects a computer, or spits out spam, or steals credit card numbers. They get better and better. Our protectors, meanwhile, struggle to keep up, designing programs that build protective walls around our computers, and filter the lottery notifications and Nigerian petroleum appeals from our inbox.