Although the SEC considers itself the "investor's advocate," it usually steps back and allows "accredited investors" and "qualified purchasers" (terms it uses for "rich investors") to invest on their own. So if Goldman Sachs and its clients are truly rich and sophisticated, I don't think the SEC will view protecting them as a good use of its time.

That being said, Goldman Sachs and its investors will likely insist on financial disclosures from Facebook and maybe even some governance rights that, while not quite public company-strength, will lead to Facebook disclosing more information to more people than it had previously.