South African computer security consultants Roelof Temmingh and Charl van der Walt were 30 minutes into their presentation at the DefCon hacker conference last week when a streaker - naked but for a paper bag over his head - sped up a side aisle and out of the front door.
The audience barely acknowledged the interruption; van der Walt made a small joke and then resumed his PowerPoint presentation on Trojan technology.
The mellow response was indicative of the laid-back atmosphere permeating this year's conference at one of the few Las Vegas hotels that still opens its doors to the hackers.
Conference organiser Jeff Moss (aka Dark Tangent) says they have been kicked out of every other establishment for past high jinks that have included putting cement in hotel plumbing.
But the casino-free Alexis Park Hotel has proved the perfect match for the conference, now in its tenth year. The hotel's bar earnings for the weekend equalled what is usually taken over eight months and in appreciation the hotel staff sported cheery "DefCon X" T-shirts.
While hacker notables such as Rain Forest Puppy were present, Deth Veggie seemed to be the only one from the hacking group Cult of the Dead Cow, which last year staged a rowdy presentation that included raw beef thrown at the audience.
A highlight this year was a war-drive through the Las Vegas Strip in search of insecure wireless networks. As the hacker caravan cruised the street, a driver who deduced their motives shouted that they would never find an open connection on the highly secure strip. Instead, he helpfully pointed them north to a string of office complexes and an array of open networks.
There were fewer US federal agents attending this year. Undercover Feds often sit on panel discussions or attend the conference to learn the community's latest tactics and trends. But this year, most federal agencies were too preoccupied with anti-terrorist activities to show up.
Rumours of foreign feds proved to be true, though, when two Frenchmen posing as a reporter and cameramen for the TV channel Canal Plus were exposed during the Spot-the-Fed contest, an annual event that awards prizes for outing undercover agents.
The more subdued tone probably reflected the increased maturity of attendees, who on average were slightly older than in the past. But it is also likely that the spectre of September 11 played a role.
Talk about legislation related to September 11, such as the Patriot Act and a proposed law that will give a life sentence to anyone convicted of a computer crime that results in a death, permeated the sessions.
Richard Thieme, a writer and former Episcopalian minister who speaks annually at DefCon and has become an unofficial father figure to the hacking community, pointed out that "the stakes are different" now.
"The game has changed. And therefore, you have to be more careful," he said. Hackers should still fight for freedom and guard against government propaganda campaigns, but they need to be cognisant of the context of their battles. In the new environment, he said, motives and methods could be easily misconstrued.
After the arrest of Dmitry Sklyarov at last year's DefCon, there were fewer exploits on open display. Sklyarov was arrested by the FBI for violating the Digital Millennium Copyright Act after demonstrating a program for cracking Adobe's eBook encryption.
The only talk that promised to rival Sklyarov's this year was a demonstration on turning off the protective Macro Vision in videos to make digitally pure copies.
Any underground nature of the talk was spoiled by the attendance of the speaker's mother, grandparents and girlfriend, proudly videotaping his appearance. His mother, however - just to be on the safe side - turned out to be a copyright lawyer.
© Sydney Morning Herald