With more than 4,000 attendees, this year’s Black Hat conference at Caesar’s Palace didn’t put much of a dent in the usual jam-packed streets of Las Vegas in August, but it certainly overflowed the hosting hotel’s convention center. Standing-room-only crowds for the keynotes and technical sessions were common, and wading through the hallway near the vendor booths was often problematic.

Seats for Richard Clark’s Black Hat-opening keynote came at a particular premium: More than half the attendees saw and heard his comments via a video feed from a back-up room.

Clark, now chairman of Good Harbor Consulting but formerly a chief counter-terrorism adviser on the U.S. National Security Council for Presidents Clinton and George W. Bush, spent the first portion of his keynote talking about the convergence of nanotechnology, IT and robotics. Clark called nanotechnology the “ultimate human-machine interface that’s going to change the nature of the society we’re in — in your lifetime.”

When he finally touched on security — the focus of Black Hat — he said it was dangerous to continue driving global business initiatives into cyberspace. The problem: “We’ve still secured very little of cyberspace.”

Clark urged Black Hat attendees to continue to ferret out software vulnerabilities and to bring them to the attention of the vendors who develop unsecure commercial products. He also urged them to work to make changes in government and industry policies and practices that hamper security advances, noting that “Congress doesn’t get it” when it comes to securing cyber space.