If Facebook were to pay taxes "where the real business is done" (assuming there is a legal way to avoid doing so), it would probably be considered gross negligence. I imagine the same is true of any multinational.

Besides, Facebook can put that money to much better use than government. All the lowly users of Facebook on the other hand do not know how to best spend their money and had better hand it over. Zuck says so (so do Gates and Soros).