The 6,780 reports date back to 1990 and comprise all of the digitized reports accessible by congressional offices, said Wikileaks, which estimated their value at US$1 billion. They do not contain classified material, but they do cover politically sensitive topics such as social policy, defense and foreign affairs.

The reports were obtained from the congressional intranet and delivered to Wikileaks three or four weeks ago, according to Wikileaks spokesman Daniel Schmitt. Wikileaks spent several weeks organizing the documents before publishing them on Sunday. It plans to make further reports public as well, so long as its anonymous source keeps providing them.

Wikileaks said it expects the reports to give the public a better idea of the information Congress has had at its disposal, and perhaps push lawmakers into making future reports publicly available. "Legally, they belong in the public domain," Schmitt said. "It is very important for anyone who is doing research as well as the general public to have access to this information, and see what the congressional research services is [producing]."

Groups such as the Center for Democracy and Technology (CDT) have been calling for Congress to make Congressional Research Service (CRS) reports public for years, but some have argued that public scrutiny could end up politicizing what is supposed to be an objective, nonpartisan office.

When made public, CRS reports can be politically sensitive. Just three weeks ago, a CRS report questioning the legality of the Bush administration's warrantless eavesdropping program was reported in the and the