What's inside the windowless AT&T/NSA spying hub in lower Manhattan?

The windowless, 550'-tall AT&T tower at 33 Thomas Street in lower Manhattan is the building referred to as TITANPOINTE in the NSA documents leaked by Edward Snowden, and was likely the staging point for the NSA's BLARNEY operation, which illegally spied upon communications to and from "International Monetary Fund, the World Bank, the Bank of Japan, the European Union, the United Nations, and at least 38 different countries, including U.S. allies such as Italy, Japan, Brazil, France, Germany, Greece, Mexico, and Cyprus." (more")