By Joseph Menn and Jim Finkle
The head of the U.S. government's secretive National Security Agency took the unprecedented step of asking a convention of unruly hackers to join him in an effort to make the Internet more secure.
In a speech to the 20th annual Def Con gathering in Las Vegas, four-star General Keith Alexander stressed common ground between U.S. officials and hackers, telling them privacy must be preserved and that they could help by developing new tools.
"You're going to have to come in and help us," Alexander told thousands of attendees.
Alexander rarely gives speeches of any kind, let alone to a crowd of hackers, professional defenders, and researchers whose discoveries of software and hardware vulnerabilities are used by both sides.