"Necessity is the plea for every infringement of human freedom:
It is the argument of Tyrants. it is the Creed of Slaves"
William Pitt the Younger, 1793, arguing against the Fox/North government's bill to "reform" the East India company so as to provide that government with more powers of patronage. Fox had argued that the bill was necessary to save the East India Company from bankruptcy - Pitt responded with this resounding denunciation of actions taken in the name of necessity.
An excellent modern illustration of the point William Pitt was making, which refers to this quote at the end, was the speech given by Dan Hannan MEP in the European Parliament on 4th July, arguing for a proportionate response and against the wholesale removal of liberties when there is a terrorist attack.
You can see most of the speech at
And the full text in the EU's equivalent of Hansard reads as follows:
Mr President, there is a measure of hypocrisy from everybody on this issue. In the aftermath of some terrorist event the cry goes up from all the newspapers and all the politicians that something must be done: we need to intercept the data and we must not allow these people to get away on account of our namby-pamby concerns over civil liberties. Then, of course, the same newspapers and the same politicians complain furiously a few weeks later about privacy.