IN A SECRET STEP, N.S.A. EXPANDED INTERNET SPYING.

The article discusses the U.S. National Security Agency's expansion of its warrantless monitoring of Americans's international Internet traffic in an effort to discover evidence of computer hacking targeting the U.S. Topics addressed include the legality of the N.S.A.'s warrantless surveillance program, as well as efforts to increase cybersecurity under the administration of U.S. president Barack Obama.