I would argue that 'shareholders' aren't able to influence these decisions at multi-national mega corporations, because many don't even know they are shareholders. Think about Joe Blow from the US. He has a managed 401k or some such investment. He has no idea the 'low-risk' fund offered through Edward Jones invests in Intel or Google or whoever. He has no idea he plays a part in this.
I would argue that 'shareholders' aren't able to influence these decisions at multi-national mega corporations
There's such a thing as activist investors, and they seem to be gaining influence lately. From what I read in the newspaper, they're behind a lot of the changes that are starting to happen at certain multi-national oil companies.