The examples and perspective in this article may not represent a worldwide view of the subject. (March 2017) (Learn how and when to remove this template message)
In the free speech context, a heckler's veto is either of two situations in which a person who disagrees with a speaker's message is able to unilaterally trigger events that result in the speaker being silenced.
In the strict legal sense, a heckler's veto occurs when the speaker's right is curtailed or restricted by the government in order to prevent a reacting party's behavior. The common example is the termination of a speech or demonstration in the interest of maintaining the public peace based on the anticipated negative reaction of someone opposed to that speech or demonstration. The term was coined by University of Chicago professor of law Harry Kalven.
In common parlance, the term is used to describe situations where hecklers or demonstrators silence a speaker without intervention of the law.
In the United States, case law regarding the heckler's veto is mixed.  Most findings say that the acting party's actions cannot be pre-emptively stopped due to fear of heckling by the reacting party, but in the immediate face of violence, authorities can force the acting party to cease their action in order to satisfy the hecklers.
The best known case involving the heckler's veto is probably Feiner v. New York, handed down by the Supreme Court in 1951. Chief Justice Fred M. Vinson, writing for the majority, held that police officers acted within their power in arresting a speaker if the arrest was "motivated solely by a proper concern for the preservation of order and protection of the general welfare". 340 U.S. 315.
It was rejected in Hill v. Colorado (2000), where the Supreme Court rejected the "Heckler's Veto," finding "governmental grants of power to private actors" to be "constitutionally problematic" in cases where "the regulations allowed a single, private actor to unilaterally silence a speaker".
Other uses of the phrase
Heckler's veto is often used outside a strict legal context. One example is an article by Nat Hentoff in which he claims that "First Amendment law is clear that everyone has the right to picket a speaker, and to go inside the hall and heckle him or her—but not to drown out the speaker, let alone rush the stage and stop the speech before it starts. That's called the 'heckler's veto'."
In Hentoff's formulation, the heckler him or herself is the party which directly carries out the "veto" and suppresses speech. This runs counter to the legal meaning of the phrase. Note that, to a lawyer familiar with the First Amendment law, the phrase "heckler's veto" means something different from what the plain English interpretation of the words suggests. In First Amendment law, a heckler's veto is the suppression of speech by the government, because of [the possibility of] a violent reaction by hecklers. It is the government that vetoes the speech, because of the reaction of the heckler. Under the First Amendment, this kind of heckler's veto is unconstitutional.'
University of California, Berkeley Law School Dean Erwin Chemerinsky has invoked the concept in an editorial following an incident on February 8, 2010, in which heckling by individual students disrupted a speech by the Israeli ambassador Michael Oren. Chemerinsky explained that broad freedom exists to invite speakers and hold demonstrations, but that once a speaker has begun an invited lecture, “You have the right—if you disagree with me—to go outside and perform your protest. But you don’t get the right to come in when I’m talking and shout me down. Otherwise people can always silence a speaker by heckler’s veto, and Babel results”.
Michigan State University professor of political science William B. Allen has used the phrase "verbal terrorism" to refer to the same phenomenon, defining it as "calculated assault characterized by loud side-conversations, shouted interruptions, jabbered false facts, threats and personal insults".
- Hamlin, David (1980). The Nazi/Skokie Conflict: A Civil Liberties Battle. Boston: Beacon Press. p. 57. ISBN 0-8070-3230-1.
- McGaffey, Ruth (1973). "The Heckler's Veto". Marquette Law Review. 57: 39–64.
- "The Heckler's Veto: A Reexamination". marquette.edu.
- Hill v. Colorado, 530 U.S. 703, 735 (SCOTUS 2000).
- Standler, Dr. Ronald B. "Heckler's Veto". www.rbs2.com.
- Lumb, David (Feb 15, 2010). "Israel: Interrupted in Irvine". New University.
- Allen, Carol M. (2008). Ending racial preferences: the Michigan story. Lanham: Rowman & Littlefield. p. 56. ISBN 978-0-7391-2433-8.
- THE LIBERTY DAILY (27 July 2017). "Ben Shapiro Crushes Anti-Free Speech College Snowflakes Before Congress" – via YouTube.