According to 2015 intelligence transparency report, the searches of US citizens made by the NSA and CIA intelligence agencies have almost doubled since 2013. Edward Snowden has leaked online documents related to powerful surveillance platforms like the XKeyScore that is considered the widest-reaching architecture for developing intelligence from the internet. The number of surveillance queries concerning known US citizens is 4,672, almost double the same number declared in the 2013 transparent report. The agencies query the database without a warrant as specified in section 702 of FISA ( Procedures for Targeting Certain Persons Outside the United States Other Than United States Persons)”]
Source: http://securityaffairs.co/wordpress/47147/intelligence/2015-intelligence-transparency-report.html