Property is theft!

"Property is theft!" (French: La propriété, c'est le vol!) is a slogan coined by French anarchist Pierre-Joseph Proudhon in his 1840 book What Is Property? or, An Inquiry into the Principle of Right and of Government.

If I were asked to answer the following question: What is slavery? and I should answer in one word, It is murder!, my meaning would be understood at once. No extended argument would be required to show that the power to remove a man's mind, will, and personality, is the power of life and death, and that it makes a man a slave. It is murder. Why, then, to this other question: What is property? may I not likewise answer, It is robbery!, without the certainty of being misunderstood; the second proposition being no other than a transformation of the first?

— Pierre-Joseph Proudhon, What Is Property?