<p>Dear Chairmen Roberts and Hoekstra, Vice Chairman Rockefeller, and Ranking Member Harman: As you know, in response to unauthorized disclosures in the media, the President has described certain activities of the National Security Agency ("NSA") that he has authorized since shortly after September 11, 2001. As described by the President, the NSA intercepts certain international communications into and out of the United States of people linked to al Qaeda or an affiliated terrorist organization. The purpose of these intercepts is to establish an early warning system to detect and prevent another catastrophic terrorist attack on the United States. The President has made clear that he will use his constitutional and statutory authorities to protect the American people from further terrorist attacks, and the NSA activities the President described are part of that effort. Leaders of the Congress were briefed on these activities more than a dozen times.</p>