In San Francisco, two militant advocates for AIDS patients have been charged with stalking and threatening public-health officials, researchers, and reporters who have made or disseminated what they deem to be objectionable statements about AIDS prevention and the behavior of infected gay men. Naturally, with no apparent sense of irony, they assert a First Amendment defense.

The suspects, David Pasquarelli and Michael Petrelis, have been held for over a month, each on $500,000 bail. They admit that they made or encouraged "foul" late-night phone calls to the homes of officials who work at the federal Centers for Disease Control in Atlanta and others they consider the "enemies of gay people." (The phone calls began in November, after San Francisco initiated a syphilis-awareness campaign inspired by an increase in the disease among gay and bisexual men.) But Pasquarelli and Petrelis deny making the threats of violence that their targets report receiving.

"They told me they were going to hunt me down, that I was in their sights," Carl T. Hall, a science writer for the San Francisco Chronicle, alleges. Dr. Jeffrey Klausner, otherwise known on the Net as Dr. K-K-K-Klausner because of his references to quarantining sexually active infected gay men, claims that he and his family received threatening, obscene calls at home.

Of course, Petrelis and Pasquarelli have an obvious right to offend, unsettle, or denounce their ideological opponents--and a concomitant obligation to tolerate being offended, unsettled, or denounced. But they have no right to target people purposefully with plausible threats of violence, which hardly advance or encourage public debate. Their prosecution does not present a difficult legal issue so much as a controlling question of fact: Did they or did they not intentionally threaten people?

The Ninth Circuit Court of Appeals, which could eventually hear this case if it winds up in federal court, has been grappling with a very similar one for the past two years. In Planned Parenthood v. American Coalition of Life Activists, the Ninth Circuit overturned a verdict by a federal jury that hit the ACLA, a group of anti-abortion extremists, with a $100-million damage award for threatening abortion providers. In addition to circulating wanted posters that featured doctors who performed abortions, the appellants had contributed information about doctors and clinic workers to the notorious Nuremberg Files site on the Internet. That site maintained a hit list of more than 200 abortion providers, together with photographs and dossiers listing personal identifying information, such as full names, addresses, license plate numbers, and details about the subjects' spouses and children. After three doctors on the list were slain, a line was put through their names; the names of the wounded were listed in gray.

In overturning this verdict, Judge Alex Kozinski likened the alleged threats against abortion providers to the protected rhetoric of civil-rights activists that was at issue in a landmark 1982 Supreme Court case, NAACP v. Claiborne Hardware. It involved a boycott against white-owned businesses in Mississippi; one organizer, Charles Evers, was said to have threatened retaliation against people who broke the boycott: "If we catch any of you going in any of them racist stores, we're gonna break your damn neck," he exclaimed. But the Court held that these remarks were protected speech--because Evers had not "directly threatened acts of violence." (He was making a speech to a crowd, not stalking or otherwise targeting particular individuals.) Evers was guilty of rhetorical excesses, not the issuance of intentional, plausible threats. The Court also stressed that he could not be held to have intentionally incited violence.

Claiborne Hardware was rightly decided, but it is the wrong precedent for the Nuremberg Files case. Abortion activists were not sued for inciting violence but for threatening it--against targeted individuals. And context is essential in determining whether or not a rhetorical flourish is an actual threat. Anti-abortion activists issued wanted posters and hit lists during a wave of homicidal violence against clinics and clinic workers. The threats were quite plausible (people had been killed), the FBI was offering protection to targeted doctors, and one defendant, Andrew Burnett, even admitted that the threats were real: "If I was an abortionist, I would be afraid," he testified.

The ninth circuit's reversal of this verdict inspired a predictable outburst of protests among pro-choicers (and debates among free-speech advocates). The full court reheard the case last month, and the timing was not propitious for anti-abortion extremists. Fear of terrorism is much stronger these days than respect for speech. The verdict against the ACLA ought to be restored--not in reaction to September 11, and not to stop violence against abortion providers, but to punish and perhaps deter deliberate efforts to terrorize people.

If the Ninth Circuit does hold the ACLA liable for issuing actual threats, it will not be starting down the slippery slope of censorship. Reinstating the verdict against the ACLA won't deter offensive or unpopular political speech, endanger war movies and video games that glorify violence, or restrict other controversial media. The usual debates about the causal connection between disputed speech and harmful behavior are irrelevant here. Neither the Nuremberg Files case nor the prosecution of AIDS activists in San Francisco is based on claims that speech causes violence. The defendants in both cases are charged not with causing physical harm to people but with intentionally instilling fear in them. For freedom's sake, we all have to tolerate being vilified, embarrassed, or harassed, but freedom will survive if we acknowledge a right not to be terrorized.