A new proposal to control oil and gas speculation through increased taxation of capital gains made through offshore hedge funds, index funds and various other investment vehicles has sparked concern among an array of energy and tax-policy experts who monitor Capitol Hill.  An energy policy expert interviewed by the Hedge Fund Law Report expressed doubts about whether such legislation would have any effect on gas prices, and a Washington lawyer suggested that flaws and complexity would undermine the likelihood of the proposal becoming law.  Others identified additional problems with the proposal.