Dear Mark
How about you change the world in a way that you can, directly.
How about securing online privacy rights and transferring ownership of people's personal information back to them. If they wish to open it up and sell it, they can. You could create an entirely new market, a new economy, you would revolutionise advertising. You could empower people to make decisions with their life and spark competition and innovation. Remove the concept of "free" services, show the real monetary value being transferred. All within your hands today. A new vision of a world based on openess and empowerment, not secret slurping and spying.
Oh, and pay your taxes, you don't *need* to offshore and process profits through 13 business entities. You can because global legistlation is lax, but you could also go to a favela and shoot street children without much chance of being prosecuted either. It's about morality, get some, it'd look good with all your wealth.