Spam filters and other intrusion detection systems and tripwires are evolving into an immune system for the Internet.

We need an Internet immune system. There are plenty of bad guys out there, and technology gives them force-multipliers (like the hackers who run 250,000-PC botnets), says Cory Doctorow.

Still, there’s a terrible asymmetry in a world where defensive takedowns are automatic, but correcting mistaken takedowns is done by hand.