By any means necessary
By any means necessary is an English phrase or a translation of a French phrase that has been attributed to at least three famous sources. The earliest of these three sources is French intellectual Jean-Paul Sartre in his 1948 play Dirty Hands. The second is Martinican intellectual Frantz Fanon who used the French phrase in his 1960 Address to the Accra Positive Action Conference "Why we use violence".. Later, it entered American popular civil rights culture through a speech given by Malcolm X at the Organization of Afro-American Unity founding rally on June 28, 1964. It is generally considered to mean to leave open the option of all available tactics, strategies or methods for attaining of achieving desired ends, including any form or degree of violence as well as other methods typically considered unethical or immoral. It is part of a broader political idea that radical social change or liberation cannot be obtained by limiting one’s means to that which are considered "acceptable", debatably encapsulated in the suggestion by Audre Lorde that "The master’s tools will never dismantle the master’s house"

Jean-Paul Sartre 

The phrase is also a translation of a sentence used in French intellectual Jean-Paul Sartre's 1948 play Dirty Hands:

Frantz Fanon 
The phrase is a translation of a sentence used in revolutionary psychiatrist and philosopher Frantz Fanon's 1960 Address to the Accra Positive Action Conference, "Why we use violence": Violence in everyday behaviour, violence against the past that is emptied of all substance, violence against the future, for the colonial regime presents itself as necessarily eternal. We see, therefore, that the colonized people, caught in a web of a three-dimensional violence, a meeting point of multiple, diverse, repeated, cumulative violences, are soon logically confronted by the problem of ending the colonial regime by any means necessary. —Frantz Fanon, Alienation and Freedom: part 3, chapter 22, "Why we use violence". 1960

Malcolm X 

It entered the popular culture through a speech given by Malcolm X in the last year of his life. Mandela recusal 

In the final scene of the 1992 movie Malcolm X, Nelson Mandela—then recently released after 27 years of political imprisonment—appears as a schoolteacher in a Soweto classroom reciting Malcolm X's speech. Yet Mandela informed director Spike Lee that he could not utter the famous final phrase "by any means necessary" on camera, fearing that the apartheid government would use it against him if he did. Lee obliged, and the final seconds of the film feature black-and-white footage of Malcolm X himself delivering the phrase. See also 
The end justifies the means
By hook or by crook
Nation of domination
Contentious politics

References 

Political violence
Political catchphrases
Malcolm X