Powerful supercomputers are vacuuming up so much information that logs of calls to or from innocent Americans could exist in government databases indefinitely, the nation’s top intelligence official said Tuesday.

An untold number of communication logs on US citizens could exist within a NSA database of information gained through warrantless wiretaps of foreigners abroad, McConnell said, because NSA spies do not examine the full contents on all the information it collects until it has a reason to do so.

The Bush administration opposed in U.S. court on Friday an effort to peel back a secrecy lid over its domestic counterterrorism wiretapping program, which critics say infringes on privacy and rights.

“The public disclosure of the documents the ACLU requests would seriously compromise sensitive sources and methods relating to the collection of intelligence necessary for the Government to conduct counterterrorism activities.”

The FBI has quietly built a sophisticated, point-and-click surveillance system that performs instant wiretaps on almost any communications device, according to nearly a thousand pages of restricted documents newly released under the Freedom of Information Act.

The surveillance system, called DCSNet, for Digital Collection System Network, connects FBI wiretapping rooms to switches controlled by traditional land-line operators, internet-telephony providers and cellular companies. It is far more intricately woven into the nation’s telecom infrastructure than observers suspected.

The Internet is the new battleground against Islamist extremism because it provides ideology that could radicalize Westerners who might then initiate home-grown attacks, New York police commissioner Raymond Kelly said on Wednesday.

“The Internet is the new Afghanistan,” Kelly said, as he released a New York Police Department (NYPD) report on the home-grown threat of attacks by Islamist extremists. “It is the de facto training ground. It’s an area of concern.”

The U.S.’s top intelligence official has greatly expanded the range of federal and local authorities who can get access to information from the nation’s vast network of spy satellites in the U.S.

The decision, made three months ago by Director of National Intelligence Michael McConnell, places for the first time some of the U.S.’s most powerful intelligence-gathering tools at the disposal of domestic security officials.