I did a quick search on those evil Koch brothers since they are apparently poster children for the evil billionaires. It was interesting to see what they do with their money in between twirling their mustaches and tying young women to train tracks. Besides using their ill gotten gains to forward political causes they believe in they have also done the following.
David Koch - Gave $100 mil to the New York State Theatre and $20 mil to the Smithsonian Natural History Museum. His charitable foundation has donated over $600 mil to various hospitals, museums, the arts, educational foundations, etc.... since 2000.
Charles Koch - Since '04, has given $250 mil to various libertarian advocacy causes. Has also given to various scholarship funds. Has won awards for his philanthropy.
Bill Koch - Has donated to prevent the construction of a wind power project at Cape Cod.
Those horrible billionaires and their not giving to anything other than that which makes them more money.