These things are set up as LLC's - limited liability corporations. The "limited" liability doesn't apply if any fraudulent activity takes place. As someone managing other people's money, you're held to a much higher standard.
Investors are understandably (and rightfully) concerned about what goes on in a fund they've invested in - and they have the right to demand an accurate and timely account from their manager.
If you don't stick exactly to the rules as laid out in the prospectus (use any instrument not explicity defined, exceed leverage or risk mgmt guidelines, trade any security not described in the prospectus, etc), fail to provide timely and accurate accounting or misrepresent returns or positions held and you could be in significant trouble, civil and criminal, state and federal. not a good place to find yourself...btw there's no 3 strikes in the securities industry, you don't get a second chance.
If anyone is seriously considering starting a hedge fund - consult a knowledgable attorney who has experience in setting these things up, get a good accounting firm and a good administrator (if offshore)...Sure they're expensive, but you'll sleep better.