Billionaire activist investor Carl Icahn released an open letter to Apple CEO Tim Cook urging the company to buy back a lot more of its stock, saying 'the market misunderstands and dramatically undervalues Apple'. Jim Cramer says what Carl Icahn is doing to Apple is assault. Cramer refutes every one of Icahn's points. For one thing, Cramer says, Icahn is wrong when he says Apple is not buying back stock aggressively enough -- Apple is buying back faster than any other company. In his letter Carl Icahn added that the stock should be valued at $203 per share today -- that's more than double of its current $100 price. Cramer says the sum total of what Icahn is doing is picking on a winner where he used to pick on losers.