The National Security Agency is compensating for the expiration of its power to collect the American peoples personal information by logging on to Facebook, the agency confirmed on Monday. The director of the N.S.A., Admiral Michael S. Rogers, said that when parts of the Patriot Act expired at midnight on Sunday, intelligence analysts immediately stopped collecting mountains of phone metadata and started reading billions of Facebook updates instead. From a surveillance point of view, the transition has been seamless, Rogers said. While the N.S.A. has monitored Facebook in the past, it is now spending twenty-four hours a day sifting through billions of baby pictures, pet videos, and photographs of recently enjoyed food to detect possible threats to the United States. Those status updates contain everything we want to know, Rogers said. In many cases, a good deal more than we want to know. Citing one possible downside of the new surveillance regime, Rogers said that some N.S.A. analysts who now do nothing but monitor Facebook all day report feelings of worthlessness and despair. I remind them that theyre doing this for America, he said. The N.S.A.s new strategy drew a sharp rebuke from Sen. Rand Paul (R-Kentucky), who told reporters, I just blocked them. 