It is possible that a fanatical religious group will impose upon the rest restrictions which its members will be pleased to observe but which will be obstacles for others in the pursuit of important aims. (Hayek, The Constitution of Liberty, p155)
It is sheer illusion to think that when certain needs of the citizen have become the exclusive concern of a single bureaucratic machine, democratic control of that machine can then effectively guard the liberty of the citizen. So far as the preservation of personal liberty is concerned, the division of labor between a legislature which merely says this or that should be done and an administrative apparatus which is given exclusive power to carry out these instructions is the most dangerous arrangement possible.(Friedrich A Hayek, The Constitution of Liberty, 1960, p 261)
And another short quote from The Federalist Papers here. In No. 47, James Madison tells us exactly what the "concentration of the several powers in the same department" is called:
The accumulation of all powers, legislative, executive, and judiciary, in the same hands, whether on one, a few, or many, and whether hereditary, self appointed, or elective, may justly be pronounced the very definition of tyranny.
Well Hayek sure was prescient. A "fanatical religious group" is exactly what radical environmentalists are.