I'd like to hear others' thoughts and opinions on Greenpeace, as I don't actually know much about the organization. Are they an effect organization at promoting environmentalism? Should I give them money? Why or why not?
I used to be a Sierra Club member but I stopped supporting them because I feel that they don't raise enough awareness about animal agriculture and its disastrous environmental effects. Probably because most of its members are nonvegans, and so Sierra Club (like smooth-talking politicians) doesn't want to say anything that would turn off their donors and reduce their income. Is Greenpeace any better in this respect?

So I spoke with this Greenpeace guy today and he described some of the actions of Greenpeace, and from what I heard they are greatly focused on preventing oil drilling in the Arctic, and establishing marine life sanctuaries. I asked him if they encourage their members to be vegan, and emphasize the environmental problems of animal agriculture. He didn't give me a very satisfying answer; he acknowledged that mass production of crops for livestock is inefficient, but he did not say that Greenpeace put a lot of emphasis on this in their efforts to educate their members. He also described being vegan as "more of a personal choice."

Thanks for your input, everyone!