> "The US Securities Exchange Act defines market manipulation as "transactions which create an artificial price or maintain an artificial price for a tradable security"."

They are 'manipulating the market' in an informal sense, but not in the sense that actually matters. There is nothing wrong with publicly stating that you think some stock is overvalued. Particularly not if you back up your claim with some evidence, which is what Hindenburg does.

As speedybird points out, that's not market manipulation in the legal sense. And if it were, the Fortune 500 CEOs and CFOs should go to jail immediately, because they all have whole departments that release information to analysts and the public in ways intended to influence the stock price.

If that's what you're arguing for, I might be able to get behind it. But I'm definitely opposed to "pumping the market is fine but countering hype should be illegal".