The telescreen received and transmitted simultaneously. Any sound that Winston made, above the level of a very low whisper, would be picked up by it; moreover, … he could be seen as well as heard. How often, or on what system, the Thought Police plugged in on any individual wire was guesswork. It was even conceivable that they watched everybody all the time. – George Orwell, 1984

Ever since we first read those chilling words, many of us have felt a reflexive horror of being bugged, wiretapped, or (now) tracked by the FBI’s fearsomely named Carnivore program, which sifts through computer networks for evidence of crime.

And who can forget the wiretaps and buggings that fueled "the savage campaign of defamation waged by J. Edgar Hoover as head of the FBI against Dr. Martin Luther King," in the words of Rep. Barney Frank, D-Mass.? (Some have forgotten that it was Robert F. Kennedy who authorized the taps.) Presidents Roosevelt, Truman, Johnson, and Nixon also used wiretaps for political ends.

So when the government seeks broader electronic surveillance powers, as Attorney General John D. Ashcroft is doing now, a lot of us instinctively worry about unleashing some kind of Big-Brother-Hoover-Nixon monster to spy on people and then blackmail or smear them.

Now is a good time to ask whether this fear is exaggerated. The case for more surveillance is pretty obvious: We need to use every available tool to prevent the mass murders of thousands or even millions of Americans. The case against is the familiar concern that the government could abuse the new powers to destroy or damage our privacy. To strike the best balance, we must scrutinize that risk with some skepticism. What bad things could happen, and how likely are they?

Abuses are always possible, especially in wartime, when the temptations for overzealousness are at their zenith and the internal safeguards are at their weakest. "This isn’t going to be limited to suspected bombers," as UCLA law professor Eugene Volokh wrote recently in Slate. "Already the government is (wisely) considering trying to track those who financially assist terrorists; financial institutions will find their records (which may include your and my records) being investigated. There will be a peace movement, and there might be reason to suspect that our enemies will try to influence it; members of the movement might find themselves being investigated."

So this is not to suggest that Congress should give the government carte blanche-or, indeed, should give it any new surveillance powers at all unless they might help fight terrorism. While the details of Ashcroft’s proposals are complex, the fundamental question is whether the government should have a relatively free hand to spy on suspected terrorists and their associates-including people suspected of ordinary crimes or immigration violations whose possible links to terrorism may largely be a matter of hunch and speculation-without producing the specific evidence required in ordinary criminal investigations.

What dangers would such new powers present? Well, officials might be tempted to stray from their core counter-terrorism mission by going after (say) suspected drug dealers who might possibly be linked to the Medellin cartel, which has engaged in terrorism outside the United States. Officials might spy on anti-globalization demonstrators or peace protesters who throw rocks through the windows of government buildings. And they might already be using their current foreign intelligence surveillance powers to fish for evidence of terrorism by tapping or bugging leaders of Islamic and Arab groups in the United States, whose religious and political discussions are sometimes seeded with hot anti-American rhetoric.

Many and probably most of the conversations overheard and e-mails intercepted would be innocent. That’s inevitable when you throw a broad net in the hope of catching people who are very hard to find. And the tappers and buggers might well overhear intimacies or embarrassing disclosures that are none of the government’s business. But any officials tempted to abuse such information would be running very serious risks of removal from office, disgrace, and even criminal prosecution.

A major reason for the electronic abuses during the bad old days of J. Edgar Hoover was that until 1967, the Supreme Court had held that the Constitution imposed no limit on governmental wiretapping of anyone, for any reason. Nor were there serious penalties to deter Hoover from using his dirt to play politics.

Now it is a federal crime for the FBI director or anyone else to leak information gleaned from wiretaps or bugs for political ends or for other improper purposes. And now the Justice Department, FBI, and other agencies involved in surveillance are themselves scrutinized by internal and external watchdog agencies with mandates to blow the whistle on any abuses. Washington lawyer Stewart Baker, former general counsel of the National Security Agency, wrote in an online dialogue with Volokh in Slate: "As I once said to an outsider skeptical of NSA’s commitment to the law, `Why am I sure that the agency isn’t breaking the law? Because there are five outside offices with authority to audit our conduct, and those agencies are headed by five ambitious people whose careers would be made if they could uncover violations of law at NSA.’ "

And now our governmental, media, and academic elites are replete with one-time antiwar protesters and others who are quick to pounce on any sign that the FBI or other agencies are up to no good. "Defending civil liberties is at the heart of the Baby-Boomer self-image, a self-image that’s been packaged and sold to adolescents ever since," as Baker wrote. "However powerful and rich and snobbish we ex-teenagers become, we still see ourselves as rebels fighting a lonely battle against overweening authority. To make that myth work, we need an overweening authority to battle, preferably one that can’t fight back. Intelligence agencies are perfect for that role." So we have watchdogs galore.

Have any grave or widespread invasions of privacy in the past 25 years stemmed from surveillance of suspected terrorists-or of anybody, for that matter? Not that I’ve noticed. I do know of one troublesome case of suspected political abuse of information gleaned from a foreign intelligence wiretap in the 1980s.

Perhaps I’ve missed others. But I’d wager that for every such case, there have been dozens and dozens of other cases of people who have seen their privacy or reputations unfairly shredded by or in media stories unrelated to governmental surveillance. "I’d worry more about The New York Times going through my trash than about the police doing it," observes Yale law professor Kate Stith, a criminal law expert.

Of course, the notion that FBI agents may be listening in on our conversations gives us the creeps, even if listening is all they do. "You had to live," Orwell wrote in 1984, "in the assumption that every sound you made was overheard, and, except in darkness, every movement scrutinized."

But the government has only a limited number of agents to spend their time listening to wiretaps. Agency heads have little incentive to waste their time and budgets on unwarranted snooping. And they will have to justify any and all taps and bugs to their superiors, to subordinates who might blow the whistle, and to judges.

So the chance that they will tap or bug or Carnivore you or me or even the Arab-American family down the street will remain quite small. Indeed, the chance that they will spy on you is a great deal smaller than the chance that your employer is monitoring your e-mail and your Web surfing. It is probably smaller than the chance that a computer hacker will get into your e-mail or a neighborhood kid will overhear your cell phone conversation.

"Is privacy about government security agents decrypting your e-mail and then kicking down the front door with their jackboots?" James Gleick wrote in The New York Times Sunday Magazine five years ago. "Or is it about telemarketers interrupting your supper with cold calls? It depends. Mainly, of course, it depends on whether you live in a totalitarian or a free society." We live in a free one.

Eighteen years ago, in The Rise of the Computer State, the respected journalist David Burnham wrote: "The question looms before us: Can the United States continue to flourish and grow in an age when the physical movements, individual purchases, conversations and meetings of every citizen are constantly under surveillance by private companies and government agencies?"

It can. It has. And now that the computer state has risen indeed, the threat of being watched by Big Brother or smeared by the FBI seems a lot smaller than the threat of being blown to bits or poisoned by terrorists.