James Ball and Spencer Ackerman (August 9, 2013). "NSA loophole enables warrantless research for US citizens' e-mail and phone phone calls - Exclusive: Spy agency has top secret backdoor permission to lookup databases for unique Americans' communications". Glenn Greenwald and Spencer Ackerman (June 27, 2013). "How the NSA is nevertheless harvesting your on-line information". Gellmann, Barton (August 16, 2013). "NSA statements to The Post".