David D. Clark, an MIT scientist whose air of genial wisdom earned him the nickname “Albus Dumbledore,” can remember exactly when he grasped the Internet’s dark side. He was presiding over a meeting of network engineers when news broke that a dangerous computer worm — the first to spread widely — was slithering across the wires.
One of the engineers, working for a leading computer company, piped up with a claim of responsibility for the security flaw that the worm was exploiting. “Damn,” he said. “I thought I had fixed that bug.”