You do realize that a gain in net worth is not the same as income, right?
Adding some random crazy tax on people or corporations like that will simply encourage companies and people to make sure their money is not in the US, and then we'll have an even bigger problem: we'll have mcowned making stupid threads every other week whining that people and companies have their money overseas in tax havens
Exactly.
There are some fairly easy ways that this can be done though - it would be trivial, in fact.
The Bush tax cuts, specifically the capital gains / dividends tax cuts, reduced the rate on those gains from 25% to 15%. This is very beneficial to middle class people investing for retirement etc as well, and it helps prop up the markets, so eliminating it wholesale is not a good idea.
But I do not see why one could not cap that 15% rate, very easily. Just make it so the first $1 million is taxed at 15%, 1 - 100 million at 25%, and everything above 100 million at 50%.
But that won't happen, because both Democrats and Repubs are bought and paid for (noting that Obama and the Democratic Congress rolled back the SS tax and payroll tax cuts, but did not touch capital gains or dividends...).
Many corporations do pay very high taxes BTW. See the link below.
Ironically, most of the high tax paying corporations are "evil companies" noted on these forums. Exxon for example, has an effective tax rate of 42%. Chevron 43%, Conoco 45%. Other high tax paying corporations include Apple, Phillip Morris, and Intel.
http://www.forbes.com/pictures/mef45fkfh/1-exxonmobil/
Deadbeat no-tax paying corporations include Verizon, General Motors, and Bank of America. Funny we never see anyone complain about those companies :
http://www.marketwatch.com/story/10-us-companies-paying-no-taxes-2013-03-26