I first heard about this phrase during the Makah whaling coverage. A Makah person held up a sign to anti-whaling activists that said "Go Home Eco-Colonialists."

There was a paper written about the protest which outlined the Eco-Colonialists mindset. These are the bullet points.

In short the arguments used by the anti-whaling conservationists were very much like the ones used by every major colonial power to justify its actions of controlling a native population.