WASHINGTON -- U.S. National Security Agency ( NSA) and the FBI are secretly tapping directly into the central servers of nine U.S. internet companies, extracting audio, video, photographs, e-mails, documents and connection logs that enable analysts to track a person's movements and contacts over time, according to a report posted on the Washington Post's website Thursday night.

The highly classified program, code-named PRISM, has not been disclosed publicly before. According to the report, it is established in 2007 and saw exponential growth in the past 6 years. The report quoted an internal document as saying the new tool was the most prolific contributor to the President's Daily Brief, which cited PRISM data in 1,477 articles last year. "NSA reporting increasingly relies on PRISM" as its leading source of raw material, accounting for nearly 1 in 7 intelligence reports.

The technology companies all participated knowingly in PRISM operations. They include Microsoft, Yahoo, Google, Facebook, PalTalk, AOL, Skype, YouTube and Apple. PalTalk is said to have hosted significant traffic during the Arab upheavals in 2011 and in the ongoing Syrian conflict.

Another internet company, Dropbox, a cloud storage and synchronization service, is described as "coming soon."

The paper said the PRISM program appears to "resemble the most controversial of the warrantless surveillance orders issued by President George W. Bush after the al-Qaeda attacks of Sept. 11, 2001."