Marx said that private property is theft. In the Marxist vision of reality, to own something is to have stolen it from someone. Today few subscribe to this belief. We know that property is a central institution for market development and for the operation of any reasonably structured economy.
Another truism arises from the simple application of this idea to the concept of intellectual property (hereinafter “IP”): IP is equally useful to the operation of the economic system as is the private ownership of tangible goods. If the Marxist belief that private property is theft turned out to be false, so is the belief that IP is theft.
But this conclusion is not as simple as it might seem. The conceptual foundation that justifies the existence of exclusive title over tangible goods does not translate to the existence of exclusive title over ideas. In fact, it is questionable whether IP should even be considered property. Its foundations are, in most cases, very doubtful, and its existence, in every case, justifies a serious limitation on the reach that it is currently granted. In this sense, perhaps, Marx’s phrase might have had a longer and happier life if he had limited himself to stating that IP was theft.
Bullard, Alfredo, "IS INTELLECTUAL PROPERTY THEFT?" (2008). SELA (Seminario en Latinoamérica de Teoría Constitucional y Política) Papers. Paper 56.