The Trump administration has now disclosed the finding of the court, which assesses requests to carry out electronic surveillance and that was set up by the 1978 Foreign Intelligence Surveillance Act (FISA), the Wall Street Journal reported on Tuesday.
The FISA Court secretly ruled last year that the FBI made tens of thousands of unconstitutional searches into US citizens' private data, as part of its surveillance program that supposedly targets people overseas, the media report said.
The FISA Court has been repeatedly criticized by civil rights activists for being too compliant and passive in permitting massive surveillance whenever it was requested and not seeking to curb the practice.
The reports of last year's ruling revealed a rare occasion when the FISA Court has one on the record as criticizing US federal law enforcement and intelligence agencies.