Market Independence
Under current law Goldman Sachs can recommend a security, like sub-prime mortgages, to a client and at the same time decide to sell short the same product for its own account. Therefore, if it happens to own a boat load of securities that they feel are overvalued there may be a temptation to encourage their clients to buy it. Someone please post on the front page of the New York Times which congressman or senator would be opposed to changing this law along with the amount of money they received from wall street firms in the form of campaign contributions. This rule defies common sense, encourages graft and corruption.