Classified program extracts e-mail, audio, video, photos, documents and logs, Washington Post says.

The National Security Agency and the FBI are siphoning personal data from the main computer servers of nine major U.S. Internet firms, which are knowingly participating in the highly classified program, The Washington Post is reporting.

The paper writes that the agencies are "extracting audio, video, photographs, e-mails, documents and connection logs that enable analysts to track a person's movements and contacts over time."

The highly classified program, code-named PRISM, was established in 2007 and had not been disclosed publicly before. Some members of Congress knew of the operation but could not comment.

The revelation comes a day after the London-based Guardian newspaper reported that a special intelligence court had ordered Verizon to turn over call information to the NSA.

The Post identified the technology companies as Microsoft, Yahoo, Google, Facebook, PalTalk, AOL, Skype, YouTube and Apple. The cloud-storage service Dropbox was described as "coming soon."

PalTalk has hosted significant traffic during the Arab Spring and in the ongoing Syrian civil war.

Obama administration officials declined to comment for the story.