Like nearly everybody I am basing my opinion on information I am provided with and I can not say that my picture is complete (I wish it was).
Further I should state that I trust blindly any information I read from Greenpeace because they have been fighting their battle longer than most orgs and unlike most others never accepted money from politicians or industry to remain independand. Also, they do all research themselves and create their own picture by being right there where things are happening.
Greenpeace has been pointing out Exxon-Mobil for many years as the biggest polluter of all according to tests and research they make.
Exxon-Mobil has an incomprehendable amount of money at hand. If they give a couple of dollars to AWF it means nothing to them but it is a huge sum for AWF. By stating that they support AWF they misguide people and make them believe that they are doing something for the environment (=advertisment/marketing) whilst instead they continue to pollute the planet (according to Greenpeace).
At the same time it becomes more difficult for the organization to fight against their donator.
Unfortunately things are not so transparent and simple to differenciate. Their is no obvious conflict between AWF that protects wildlife and Exxon-Mobil that pollutes the environment.
WWF does well receiving "Green"- Computers from Fujitsu-Siemens as a donation rather than highly toxic Apple computers. This way they reduce the damage they produce themselves and they do well considering which products they use.
Also, most hardliners that insist on eco-tourism seem to forget the damage they still produce. What about all the jetting around across the world to get to Africa? And all the domestic flights from lodge to lodge? The luxarity they consume in those camps which needs to be flown in to the camps? All this pollution (including noise-pollution) has a drastic effect on wildlife, but no-body whants to hear about it.
What I want to say is, unless we want to become vegetarians sitting in a wooden house and only travelling as far as our feet can take us, we will need to compromise. Compromising by reducing our impact to a minimum. But this can only happen if we communicate and work together. Some companies have understood this (see the lodges/camps listed on bushdrums) but there are also a very large amount out there that simply ride the money wave of eco-tourism without truely doing something for it.
Is there an institution that controlls them? As far as I know, not. I only know of institutions that give advice. So, how is John Average supposed to know who he should give his donation to?
It is one thing if a company pays an organization for the service of making a research and it is another thing if the company makes big donations on the top of it.