Room 641A is a telecommunication interception facility operated by AT&T for the U.S. National Security Agency, as part of its warrantless surveillance program as authorized by the Patriot Act. The facility commenced operations in 2003 and its purpose was publicly revealed in 2006.

AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's fourth-largest telecommunications company by revenue and the largest wireless carrier in the United States. As of 2023, AT&T was ranked 13th on the Fortune 500 rankings of the largest United States corporations, with revenues of $120.7 billion.