I think you're equating short selling with fraudulent market manipulation. Short selling has no soul - flipping the buy-then-sell to sell-then-buy ( that is, shorting ) merely allows the pessimists to place their bets along side the optimists, and the markets are better off for it. A great read on the subject:

http://leedsonfinance.com/2009/06/13/the-sec-is-at-it-again-...