Since its founding in 1992, DefCon has been a venue where anarchists, geeks, and employees of three-letter federal agencies became unlikely comrades under a live-and-let-live credo that placed the love of computer tinkering above almost everything else. No more. As tensions mount over the broad and indiscriminate spying of Americans and foreigners by the National Security Agency, DefCon organizers are asking feds to sit out this year's hacker conference.

"For over two decades DEF CON has been an open nexus of hacker culture, a place where seasoned pros, hackers, academics, and feds can meet, share ideas and party on neutral territory," Jeff Moss, aka The Dark Tangent, wrote in a blog post published Wednesday night. "Our community operates in the spirit of openness, verified trust, and mutual respect."

He continued:

When it comes to sharing and socializing with feds, recent revelations have made many in the community uncomfortable about this relationship. Therefore, I think it would be best for everyone involved if the feds call a "time-out" and not attend DEF CON this year. This will give everybody time to think about how we got here, and what comes next.

DefCon, which is scheduled to run August 1 through 4 this year at the Rio, has almost always gone out of its way to welcome federal agents. The annual pilgrimage to Las Vegas during the dead of summer has long been famous for its "spot the fed" contest. Former federal prosecutor Curtis Karnow spoke at the inaugural event, according to this DefCon press archive. US Department of Defense Director Jim Christy has been attending since 1999 in an open campaign to attract top hacker talent to the ranks of military and federal agencies. Still, many more agents prefer to attend under the shadow of anonymity.

In many respects, the ties between DefCon and the federal government only strengthened in recent years. In 2009, Moss joined the Homeland Security Advisory Council, a post under which he advised Secretary Janet Napolitano on matters of computer security. And last year, National Security Agency Director Keith Alexander gave the DefCon keynote address, marking the highest-level DefCon appearance by a US government official.

But in other respects, tensions seemed to mount between feds and more civil liberties-focused DefCon attendees following the 9-11 attacks of 2001. In recent weeks, amid leaks by former CIA contractor Edward Snowden exposing a spying program many say is intrusive and unconstitutional, things have reached a breaking point, some hackers said..

"While not new, I feel a mood in the hacker community that has resurged to levels I’ve not seen in years," Kyle R. Maxwell, a security analyst for one of the telecoms recently implicated in the NSA dragnet, wrote in a blog post reacting to Wednesday evening's announcement. "The Snowden affair really only brought to the fore problems that seemed to worsen during the Bush administration, then got quiet when many people felt that perhaps things will change under President Obama. Clearly, that was not the case by any stretch of the imagination."

It's unclear how forcefully DefCon organizers will discourage feds from attending this year's conference or whether any federal officials are scheduled to speak this time around. Moss and other DefCon officials didn't respond to an e-mail asking for clarification. What is clear is that growing tensions have triggered a seismic rift in hacker-fed relations that won't be easy to mend.