It was probably a typo, or a spell checker correction gone wrong, but this caption under a photo in a newspaper movie section startled me into a post:
Corsican crime boss Cesar (Niels Arestrup) is the de factor head of the prison in which Malik (Tahar Rahim) finds himself in Jacques Audiard’s A Prophet.
The correct spelling is de facto.
As a legal term, de facto is usually opposed to the term de jure.
de facto [dĭ făk’tō,]: in fact, in reality, in actual existence, force, or possession, as a matter of fact.
de jure [dē jʊr’ē]: of right, by right, according to law.
Here are examples of de facto used on the web:
De facto disenfranchisement has devastating long-term effects in communities across the country.
Remember: A de facto parent is not the same as a parent.
One very widespread phenomenon that calls strongly upon the conscience of the Christian community today is the growing number of de facto unions in society as a whole, with the disaffection for the stability of marriage that this entails.
Here’s one with de jure:
The Supreme Court first approved of de jure segregation in Plessy v. Ferguson (1896)
Here’s an example that contains both de facto and de jure:
Outside the ministries, alongside the baby blue of the UN ﬂag, stands the black double headed eagle and blood red backdrop of the Albanian ﬂag, Kosovo’s de facto ﬂag… Perhaps the only thing that is clear in Kosovo is that there is a huge divide between the de jure status of this piece of land and the de facto reality on the ground.
Two other “facto” terms are ipso facto and ex post facto.
ipso facto [ĭp’sō făk’tō]: By that very fact; by the fact itself.
If you grow up in Brooklyn, you’re a New Yorker ipso facto. —Norman Mailer
It’s Cold! Ipso Facto, Global Warming is a Myth, Fraud, Scam. –ironic headline
In 1883, on the death of Pusey, [Samuel Driver] became Regius Professor of Hebrew at Oxford and (ipso facto) a Canon of Christ Church.
People apparently love the sound of ipso facto. The phrase is popular with entertainment groups and merchants.
Ipso Facto is a great new shop in Three Oaks, Michigan.
Ipso Facto Gothic Industrial Punk fashion and music webstore featuring gothic dresses, gothic shirts, gothic skirts
In 1986 Wayne left Shangoya and started a band named Ipso Facto
Ipso Facto was an overlooked, esoteric gothic band from the UK in the 80s.
ex post facto [ĕks’ pōst făk’tō]: Done after another thing, and operating retroactively. The term is usually used in reference to a law that would punish a person for having done something that was not against the law when it was done.
2008 Alaska Rules Ex Post Facto Registration Unconstitutional
The Constitution provides important safeguards against government regulation of private conduct in both the civil and criminal contexts – including the Ex Post Facto Clause, which protects against the retroactive application of laws. –Scotusblog
The Lautenberg Amendment has faced several challenges in federal court. Opponents of the law have argued that the amendment violates the … Ex Post Facto Clause…