If Greenpeace is a menace to the world, then it deserves a subsidy commensurate with other menaces to the world. Is Greenpeace at this point worse than agriculture or forestry or armaments industry or aviation industry, etc. by the damage it inflicts upon society and nature outside?  Such a question must be politically permitted before it can answered by whatever technique that is also politically permitted. Science serves its master, the political system, unless science is the master of the political system: The latter would seem to be the logical conclusion of the enlightment project of global plundering. 

Greenpeace yet lacks negative liabilty: It doesn't appear to be in the same league as our institutions. With negative liability, Greenpeace could be reformed, and many wonderful positive externalities could erupt.