We can argue about whether money should be taxed when it is given to you (income tax) or when you give it to someone else (sales tax, gift tax, inheritance tax) or whether it should even be taxed at all, but the reality is this--as @AshburnerX says above, the people who have dedicated their lives to the growth and accumulation of money (like, for example, hedge fund managers) are also the people least likely to feel any sort of social responsibility. As such, in order to get them to contribute to society as a whole, they must be forced to do so though mechanisms like taxation, because otherwise they would happily sit on their piles of money, continuing to build their private little dynasty and watching the world crumble around them, so long as everybody else keeps their hands off of their stack. And I don't wanna hear anything about "That's Government interference, they earned that money, therefore it's theirs to do with or not as they will," because that's just as ludicrous as suggesting that everyone else should work for no wages, merely the satisfaction of a job well done, in order for Mr. Rich Guy's fortune to be permitted to grow at its maximum possible speed.Maybe the REAL problem is that income taxes are just a bad idea poorly executed in just about every situation.
--Patrick