David Burnham is a reporter in The Times's Washington bureau. This article is adapted from Mr. Burnham's book ''The Rise of the Computer State,'' to be published by Random House in May.
A Federal Court of Appeals recently ruled that the largest and most secretive intelligence agency of the United States, the National Security Agency, may lawfully intercept the overseas communications of Americans even if it has no reason to believe they are engaged in illegal activities. The ruling, which also allows summaries of these conversations to be sent to the Federal Bureau of Investigation, significantly broadens the already generous authority of the N.S.A. to keep track of American citizens.

The link for this article located at NY Times is no longer available.