Unclassified Report on the President's Surveillance Program, The Office of the Inspectors' General of the US Department of Justice (DOJ), the National Security Agency (NSA), the Central Intelligence Agency (CIA), the Department of Defense (DOD), and the Office of National Intelligence (ONI), July 10, 2009 [reporting that the Bush administration's warrantless wiretapping program relied on a flawed legal analysis at its inception and produced results of questionable effectiveness].
Reported in JURIST's Paper Chase here. Latest commentary available here. JURIST has more on wiretapping.