By John Shiffman and Mark Hosenball (Reuters) WASHINGTON - U.S. intelligence officials on Tuesday identified two of the more than 50 classified cases in which they say National Security Agency eavesdropping helped thwart terrorist plots including a planned attack on the New York Stock Exchange. The other, a San Diego money laundering investigation tied to financing for a Somali militia, is among the 27 cases cited in a Reuters report Tuesday in which the U.S. government filed public notice that it used a Foreign Intelligence Surveillance Act warrant. ...