It may not be strictly criminal, but the influence that these multinationals have to subvert and corrupt governments is monumental and that is highly unethical. Nobody should be defending multinationals in this situation, their profits are for them alone. E.g. a mining company moves in, sucks the land dry, doesnt pay any substantial tax and then leaves, often with the people of that country worse off than before. This sort of unethical behavior is cancerous and enables modern day economic slavery.