In my experience, there are several well funded groups that push their agenda and initiate lawsuits. Activists for many wildlife causes. Friends of Animals, PETA, Green Peace and others. They solicit money from people by advertising with heart touching photos of starving animals or a wolf in a trap, etc. They take in some big money and I believe that it's just a big business to the upper end of the organizations.
The organizations are generally made up of some pretty radical anti-hunters but they also oppose whaling and take-on environmental issues that they disagree with. Some of the things they stand for I agree with, but I never support their organizations due to the hardcore anti-hunting stance.
They do push their agendas worldwide. When Alaska's Game Board would address some wolf related issue, we would receive thousands of form letters in opposition to wolf management, from all over the U.S. and foreign countries. Often the propaganda that they pushed was completely false but it stirred the emotions and got donations from a lot of well meaning, but mislead people.
These organizations are a big reason why hunters/trappers, etc. need to be doing things ethically and smart. It's also why I join more science based organizations like the Elk Foundation, SCI and some others, that are not based on emotion and some cherry-picked photo of a starving wolf in a trap.
Now, on the idea of introducing apex predators into areas that don't have them, I don't support it. I prefer natural territorial expansion and active management, but that's just me.