There is a rumor that the FBI isn't letting any other agencies into the building. If they had lost access to something in there for whatever reason, they are in now.
I doubt the FBI wouldn't at least let the ATF or the NSA access the building. The NSA probably has their own shit in there, and the ATF would see that as part of their jurisdiction anyway. Keeping the FCC out? sure.
There is a rumor that the FBI isn't letting any other agencies into the building. If they had lost access to something in there for whatever reason, they are in now.
I doubt the FBI wouldn't at least let the ATF or the NSA access the building. The NSA probably has their own shit in there, and the ATF would see that as part of their jurisdiction anyway. Keeping the FCC out? sure.