A chilling effect is a term in law and communication which describes a situation where speech or conduct is suppressed by fear of penalization at the interests of an individual or group. It may prompt self-censorship and therefore hamper free speech. Since many attacks rely on libel law, the term libel chill is also often used.
In United States
and Canadian law
, the term chilling effects
refers to the stifling attribute that vague or overbroad laws may have on legitimate speech activity. Recognition of a law that may permit a loophole for such chilling effect
as a vehicle for political libel
or vexation litigation
provides a prompt to allow changes to such defamation
laws, and therefore prevent the suppression of free speech and censorship.
The term chilling effect
had been in use in the United States since as early as 1950
. It however became further used as a legal term when William J. Brennan
, a justice
of the United States Supreme court, used it in a judicial decision (Lamont v. Postmaster General
) which required a postal patron receiving "communist political propaganda to specifically authorize the delivery.
The Lamont case however, did not center around a law that explicitly stifles free speech. A "chilling effect" referred to at the time a "deterrent effect" on freedom of expression — even when there is no law explicitly prohibiting it. However in general, "chilling effect" is now often used in reference to laws or actions that do not explicitly prohibit legitimate speech, but that impose undue burdens.