They don't exactly disclose their activities publicly.
It stands to reason that a major telecommunications node would be involved with some sort of surveillance program, though I guess that it probably depends on the exact nature of a particular place. Presumably, they would want to cover the entire communication that goes in and out and as much of internal stuff as they can, with as little on the ground involvement as possible. I'm just talking, look into the specific programs for anything concrete.
It is important to note that this building is telephone stuff, so it's kinda retro, and (much more important nowadays, and more of interest to people here, I guess) internet data is covered by PRISM, which is an entirely different program operating on a different basis.
As we all know, many chunks of NSA surveillance-related information have been made public, so you should probably consult them for specifics, and find out what this building next to you does, exactly, to know where to look. You would probably want to start with some vague secondary source, even Wikipedia, because these data dumps are humongous.