Room 641A is a secret room in a building in San Francisco, California. It was set up by AT&T, the phone company, in order to collect information from phone calls and emails that passed through their network. The room was set up in 2003 and was not revealed until 2006, when the U.S. government found out about it and started an investigation. Room 641A was set up to collect information from people's phone calls and emails. It gathered information from people's conversations, who they were talking to, and what they were saying. It was not just used by the U.S. government, but also by other countries, businesses, and even criminals.