John Ashcroft, who was a proponent of encryption and privacy as a U.S. senator and a champion of expanded Internet surveillance as the nation's attorney general, resigned on Tuesday.

During his controversial tenure as the nation's top law enforcement officer, Ashcroft, 62, earned the lasting enmity of civil libertarians for his attitude toward privacy after the September 11, 2001, terrorist attacks. He backed additional Internet surveillance, expanded use of secret "national security" letters to obtain customer data from telecommunications companies, and revising the Patriot Act to make it permanent.

Under Ashcroft, the Justice Department ramped up online obscenity prosecutions and--after suffering a severe setback from a federal appeals court--settled the Microsoft antitrust case filed in 1998 under the Clinton administration.

However, Ashcroft's resignation, which will take effect when his eventual successor is confirmed, may not herald a dramatic shift in Justice Department priorities.

Adam Thierer, director of telecommunications studies at the free-market Cato Institute, said there is an "institutional culture that is going to rail for these sorts of causes and issues no matter who's on top."

On September 13, 2001, two days after the attacks on the World Trade Center and the Pentagon, the Justice Department persuaded the Senate to approve surveillance legislation, which already had been circulating in the Clinton administration. In a demonstration of institutional unanimity, a report released last month calling for sweeping new copyright police powers was endorsed by no fewer than five assistant attorneys general at the Justice Department. The FBI's push for voice over Internet Protocol (VoIP) surveillance continues an effort that Attorney General Janet Reno and FBI Director Louis Freeh began more than a decade ago.

In a message to Justice Department employees late Tuesday, Ashcroft took credit for thwarting additional terrorist attacks and said the department should be proud of its "extraordinary era of justice and security."

Ashcroft's tenure as attorney general was defined primarily by September 11, 2001.

When Ashcroft was in the Senate before his defeat in 2000, he was a leading advocate of online privacy and encryption. "The Fourth Amendment neither prohibits nor permits all searches--it recognizes the legitimate needs of law enforcement by authorizing reasonable searches and respects individual privacy by prohibiting unreasonable searches," Ashcroft said at the time. "A key to every home, diary, bank account, medical record, business plan or investment (must not) be provided to the federal government for use without the individual's knowledge."

But after the 2001 attacks, Ashcroft was offering unflattering characterizations of civil libertarians. "To those who scare peace-loving people with phantoms of lost liberty, my message is this: Your tactics only aid terrorists--for they erode our national unity and diminish our resolve," he told the Senate in December 2001.

The American Civil Liberties Union returned the favor in a statement on Tuesday that accused Ashcroft of having a "radical agenda" including assertions--many rebuffed by the courts--that the U.S. government can indefinitely detain U.S. citizens in secret.

"With key parts of the Patriot Act set to expire next year, the next attorney general must be willing to listen to the millions of Americans who live in communities that have passed resolutions asking that the Patriot Act be brought back in line with the Constitution," the ACLU said. "Proper checks and balances against government abuse must be restored."

The resignation of Ashcroft and Commerce Secretary Don Evans, also announced Tuesday, represent the first of what is expected to be a series of departures from President Bush's Cabinet before the January inauguration.

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