by J. Bravin Feb 27, 2013 p. A2
[paraphrasing] The Supreme Court ruled that the government does not need probable cause for blanket monitoring of international communication between people in the US and those overseas.
Majia here: In 2008 the Foreign Intelligence Surveillance Act (FISA) authorized mass surveillance and does not require identification of specific targets. The Supreme Court upheld the law.
Reuters provides more background http://www.reuters.com/article/2013/02/26/us-usa-court-surveillance-idUSBRE91P0JS20130226