In the brouhaha recently over a Gainesville minister’s threat to burn copies of the Quran, a consensus emerged that no matter how nutty and offensive the idea was, the preacher and his parish had a constitutional right to follow through with it. (Thankfully, they refrained.)

Now comes one voice of potential dissent — a person with the power to actually determine whether such an act could be made illegal.

In a recent interview, Supreme Court Justice Stephen Breyer indicated that the threat of violence by offended Muslims could justify exempting Quran burning from the kind of First Amendment protections that are afforded similar acts of expression, such as torching an American flag.

His logic is alarming. Legitimizing a “heckler’s veto” of speech would be a serious blow to one of our most cherished constitutional freedoms.

The interviewer, George Stephanopoulos asked Breyer: “When you think about the Internet, and when you think about the fact that a pastor in Florida, with a flock of 30, can threaten to burn the Quran and that leads to riots and killings in Afghanistan, does that pose a challenge to the First Amendment and how you interpret it? Does it change the nature of what we can allow and protect?”

The justice responded: “… (W)ith the Internet, you can say this. You can’t shout fire in a crowded theater. (Justice Oliver Wendell) Holmes said it doesn’t mean you can shout ‘fire’ in a crowded theater. Well, what is it? Why? Because people will be trampled to death. And what is the crowded theater today? What is being trampled to death? It will be answered over time in a series of cases which force people to think carefully.”

Granted, Breyer was speaking off the cuff, hypothetically and vaguely so as not to bias himself against future court cases he might have to rule on. Nevertheless, the potential justification he raises is troublesome.

First, Holmes Jr. in 1919 said you cannot falsely shout “fire” in a crowded theater. Anyway, he later softened his stance and the court has since refined its standards for protecting inflammatory speech. The threat to human life must be direct and imminent.

Next, Breyer suggests the Earth itself is a crowded theater, meaning any one of its nearly 7 billion inhabi-tants could be incited to violence by something someone somewhere else on the planet says or does because the Internet can disseminate the message. By that standard, everyone should keep their mouths shut.

The key question, though, is why burning a Quran is different than burning a U.S. flag, something the court protected in Texas v. Johnson (1989). A five-justice majority explicitly rejected the claim that flag burning should be prohibited because it might disturb the peace.

And why is desecrating a Quran somehow more offensive than allowing neo-Nazis to march through a predominantly Jewish neighborhood? That, too, is expression protected by the First Amendment.

Breyer’s ruminations flirt with endorsing the idea that rioters can be allowed to intimidate political opponents into silence. When that conflict arises, the government has the responsibility to protect the speaker from harm, not muzzle him.

Finally, just because the Internet has grown the audience doesn’t mean our freedoms should be diminished.