Since the basic aim of any company is to maximize profit while staying within the boundaries of the law, I'm inclined to go with the idea that companies do not hold any more social responsibility than the law forces them to. Or saying that another way, basically that they can technically disregard social responsibility as far as the law will allow them to.
Here are the lines along which I'm thinking right now..McDonalds aren't responsible for people being fat, McDonalds are under no obligation to look out for the health of people who can't control their diet. McDonalds have one aim, to be profitable. That sort of thing.
What do you think when you think about big (or small even) companies and social responsibility? All ideas welcome, thanks!