No I cannot, because this individual stated that "a 3 letter federal agency" operates the node. Thus never really saying it was the NSA. Given the recent news though, one can only guess it was the NSA.
Is it really that hard to believe? Considering that the Georgia Tech Research Institute (GTRI) gets mostly DoD contracts and research grants and a lot of those contracts are for classified projects.
When I was in college, we always heard rumors of CIA doing this and NSA doing that... with the exception of the few NSA mathematicians who took sabbaticals in our math department, I generally assumed it was BS. (They were really nice guys, by the way. I learned elliptical factorization from one of them. Sure wish I remembered it!) This was the late 90s, not the heydey of LSD research and all that crazy stuff. I only wish...
Now, as for DoD funding institutional research, absolutely (they funded me last year for something completely benign and outside the scope for "info wars"). They fund research at a lot more places than GT. So, yes, plausible. But, unlikely IMO that NSA has an active presence on your campus doing intelligence work.
BTW, I challenge your claim that GT gets "mostly DoD". I'm sure your school is primarily funded by NSF (the preferred government tit to suck on). DoD is actually a pain in the ass to deal with because they don't go away after the money changes hands. Same is true for SBIR/STTR.
Finally, DoD classifies everything. Don't let that label fool you into thinking the work is sensitive (or even interesting). Within academia, this is less so because the objective of funding institutional research to produce publications. Contract R&D is not something that is popular with faculty (or the school, since depending on the IP ownership, it can put their tax exempt status at risk.)
That said, keep snooping and let us know what you find in that room labeled "no personnel permitted without super-duper top secret clearance".
No it is not hard to believe that NSA doles out a lot of research money to schools across the country. Information Assurance is one of NSA's core missions.
I do not mean this to be snarky -- if you have a legitimate source other than hearsay, I'd love to see it.