If it's an old AT&T building, then the way it's built is in tradition with the AT&T style. They tended to build large, multi-story COs with no windows (or minimal windows.) Easier to keep them climate conditioned inside, and it keeps prying eyes off the merchandise while giving the maximum amount of floor and wall space for equipment. Ma was very secretive about her goods, and you know she cooperated with the government when asked to. There are exceptions, of course, but that's the way Ma used to operate.