“Copyright is monopoly, and produces all the effects which the general voice of mankind attributes to monopoly. […] Monopoly is an evil. For the sake of the good we must submit to the evil; but the evil ought not to last a day longer than is necessary for the purpose of securing the good.”

May the Source Be With You (2001)
Context: While control is needed, and perfectly warranted, our bias should be clear up front: Monopolies are not justified by theory; they should be permitted only when justified by facts. If there is no solid basis for extending a certain monopoly protection, then we should not extend that protection. This does not mean that every copyright must prove its value initially. That would be a far too cumbersome system of control. But it does mean that every system or category of copyright or patent should prove its worth. Before the monopoly should be permitted, there must be reason to believe it will do some good — for society, and not just for monopoly holders.

Source: The Production of Security (1849), p. 34-35
Context: Everywhere, when societies originate, we see the strongest, most warlike races seizing the exclusive government of the society. Everywhere we see these races seizing a monopoly on security within certain more or less extensive boundaries, depending on their number and strength.And, this monopoly being, by its very nature, extraordinarily profitable, everywhere we see the races invested with the monopoly on security devoting themselves to bitter struggles, in order to add to the extent of their market, the number of their forced consumers, and hence the amount of their gains.War has been the necessary and inevitable consequence of the establishment of a monopoly on security.Another inevitable consequence has been that this monopoly has engendered all other monopolies.

Source: The Production of Security (1849), p. 34-35

[OpenBSD's Theo de Raadt talks software security, Gedda, Rodney, Computerworld, http://www.computerworld.com.au/index.php/id;1498222899;fp;16;fpid;0, 2004-10-09, 2007-01-10]
speaking about OpenSSH.

Source: Blood in My Eye (1971), p. 109

As quoted in Margaret Mead : Some Personal Views (1979) edited by Rhoda Métraux
As quoted in American Quotations (1992) by Gorton Carruth and Eugene H. Ehrlich
1970s
Variant: At times it may be necessary temporarily to accept a lesser evil, but one must never label a necessary evil as good.

In "The Law and the Future," in The public papers of Chief Justice Earl Warren (1959) edited by Henry M. Christman .

Political Theology (1922), Ch. 1 : Definition of Sovereignty