The famous Def Con conference has been the neutral ground for hackers, geeks, feds and anarchists for over 20 years, but feds are not welcome anymore.

In light of the recent PRISM controversy, with growing concerns over the National Security Agency's (NSA) broad and indiscriminate spying of Americans and foreigners alike, Def Con organizers have politely asked feds to sit this one out.

"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. Our community operates in the spirit of openness, verified trust, and mutual respect," wrote Jeff Moss, a.k.a. The Dark Tangent, in a blog post.

"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."

In other words, if in previous years the Def Con welcomed federal agents with open arms, this is no longer the case. The annual conference famous for its "Spot the Fed" contest is now closing its doors to representatives of the Federal Government.

In past years, when the feds were not blacklisted, Def Con seemed like a perfect meeting place for hackers and feds. According to a Def Con press archive, former federal prosecutor Curtis Karnow spoke at the inaugural event 20 years ago. U.S. Department of Defense Jim Christy has also been a regular attendee since 1999, as part of an open campaign to recruit top hackers for the military and federal agencies. Other feds, meanwhile, chose to attend the show anonymously, that is until they were spotted.

The close ties between Def Con and feds grew even stronger as years passed by. The Dark Tangent himself joined the Homeland Security Advisory Council back in 2009, advising Secretary Janet Napolitano on matters relating to computer security. Last year's keynote address, meanwhile, was delivered by none other than NSA director Keith Alexander.

All attendees, be they hackers, anarchists, feds, or just computer enthusiasts, formed unlikely bonds during the conference, placing their passion for computers above any rank or position. The NSA, however, seems to have ruined that.

This year's Def Con hacker pilgrimage will take place on August 1-4 at the Rio Hotel and Casino in Las Vegas, Nevada, and feds who were planning on attending the conference would better reconsider. For the first time ever, federal employees are not welcome.