No offense intended, but this is a biased and exceptionally naive viewpoint. If you had an equal amount of awareness of the mission and mandates of FBI and the things the Bureau is already overwhelmed with, such as national security, terrorism and counterterrorism, espionage and counterintelligence, organized crime, illegal drugs, illegal guns and other weapons, racketeering, transnational criminal enterprises, white collar crime, violent crime, human trafficking,
significant cyber crime, public corruption at all government levels, and how difficult and time consuming even simple investigations can be, and that FBI does not investigate innocent civilians without reasonable suspicion, probable cause and due process, you'd realize they literally would have no concern about Defcon even after one of their own agent researchers prepared a report showing they were mocked. We really
do not want to know what horrible things FBI is working against because it would cause significant psychological damage to any not already in law enforcement.
NSA will be even less interested because their mission excludes domestic activities, and they are probably tapping every foreign telephone and monitoring and recording massive amounts of foreign Internet traffic, upwards of 2B emails a day, as well as radio and television broadcasts, and printed media. The amount of data NSA sifts through on a daily basis is mind-boggling. It would be astoundingly irresponsible if they wasted any resources whatsoever on Defcon, even a single employee to sit in a booth for a day. It is far more likely to be arranged by Defcon organizers rather than there being any interest whatsoever in a commercial convention and its participants, who are more than welcome to fill out and submit job applications on their own if the interest exists. NSA attracts so much talent as it is, they would never need to poach hackers from Defcon. The conventions these agencies attend you never hear about and would never admit the happy go lucky public participants of Defcon. I am not suggesting there isn't talent attracted to Defcon, only that the fact that these individuals even attended make them inappropriate candidates for recruitment by NSA, which is a spy agency. Spies do not show off their tradecraft in public or walk around with their mouths agape overwhelmed by the flashy commercialism of public conventions. By and large they are extremely patriotic and take their jobs deadly seriously, and Defcon could never be described as serious by design. Defcon is for fun, it is commercialized entertainment.
That said, federal agents are as free as anyone to moonlight even for entertainment purposes so long as they don't violate off-duty conduct codes of their agency and DoJ. But the agencies themselves could never have interest in Defcon in any official capacity unless there was actually a valid reason, and a bunch of hackers having a good time is not a valid reason. There would need to be a threat to national security or reasonable suspicion of federal crime. Defcon isn't like that.