By web search, there are 614 billionaires in the US. Let's say you took an extra 100 million dollars from each of them every year: $61.4 billion. The total annual tax revenue in the US is almost $4 trillion--that is 4000 billion. $61.4 billion is a drop in the bucket. In my opinion, the numbers don't warrant all of the hand-wringing about billionaires--whose worth is largely invested capital which stimulates the economy.