I propose that we will make more progress in our inquiry if we re-frame how we approach the matter. These articles (viz. Apple and Microsoft) have generated a lot of traffic because there is a tacit expectation that corporations have moral responsibilities or are moral actors. I want to challenge those assumptions.
To assign feelings to corporations is anthropomorphic: Apple cannot hate (or love) America any more than a colony of bacteria can hate or love a petri dish. A corporation will seek to minimize its tax burden the same way a simple organism unpleasant stimulus in its environment. Casting that behavior as moral or immoral is a fallacy. It is an easy mistake to make because every behavior a company exhibits is an expression of a decision made by a person. People are moral actors endowed with individual wills, conscience, and (hopefully) a moral compass.
There does not have to be any conscious evil unpinning corporate behavior for a corporation to behave in ways that feels immoral or amoral to us. For example, if a finance executive can reduce a corporation's tax burden by taking steps that are not demonstrably illegal, that exec will prosper. His superiors will reward him and entrust him with more power. His rival will fall by the wayside. If a financial executive's moral compass caused him to make decisions that were not in the corporation's best interests, the corporate body will expel him, just as a living body might try to eliminate a cancer.
The system rules by which corporations act are observable and remarkably consistent. This might be useful. For example, the phenomenon that water tends to run down hill is also observable and remarkably consistent, and this simple observations leads us to build damns to store potential energy, irrigate crops and control flooding.
The turning point comes when we stop asking "how can we make corporations to behave like good citizens" and start asking "how can we best harness corporate behavior for the good of the citizens". If I had the answers, I'd try and write a book instead /. post. Approaching the problem from a new perspective might lead us to some new territory we haven't already covered.