In the space of a week, Facebook has gone from inking a deal with Goldman Sachs for a special purpose vehicle that would allow for investment in the company without financial disclosure, to a pledge to either go public in 2012 or submit all its financial disclosure information publicly. Facebook is more of a retailer than Goldman Sachs, and responded to the controversy over its “privacy for me but not for thee” approach accordingly.

But this hasn’t stopped the SEC from questioning Goldman Sachs over the deal, both on the special purpose vehicle created and what amounts to the marketing of the deal through the media.

Federal and state securities regulators prohibit the use of what the laws describe as “general solicitation and advertising” in private offerings. Companies or investment firms like Goldman that seek to raise money through a private offering cannot do anything that would be considered publicly promoting the deal, like an advertisement in or any communication to a media outlet. A violation of these rules could jeopardize an offering.

“There is not a lot of S.E.C. guidance in this area,” said Udi Grofman, a lawyer at Schulte Roth & Zabel who specializes in private offerings. “While the S.E.C. has offered some guidance on what constitutes general solicitation or advertisement, the question of whether the issuer or anyone on its behalf tries to create ‘hype’ or interest in the offering is very fact-specific.” [...]

The S.E.C.’s interest in Goldman’s Facebook deal adds a new twist to an inquiry the agency began last month into the rapidly growing trading market for private share offerings of hot Internet companies, including Facebook, Twitter, LinkedIn and Zynga.

Obviously, the heavily-hyped report on Facebook and Goldman helped drive customers to the deal, and if it becomes somewhat standard, you could have this off-exchange set of investments with no transparency.

And this isn’t the only deal of Goldman’s that has aroused skepticism.

A foundering bond insurer filed a civil fraud suit against Goldman Sachs Thursday over the same exotic mortgage securities deal in which Goldman paid $550 million last summer in a settlement with the Securities and Exchange Commission.

ACA Financial Guaranty Corp. charged that Goldman helped a major client, the hedge fund Paulson & Co., rig the billion-dollar deal by allowing the firm to pack it with securities backed by highly risky mortgages in early 2007 as the housing market was beginning to collapse.

ACA invested heavily in the deal, known as Abacus 2007-AC1, in the belief that Paulson had agreed to absorb the first losses, while Goldman concealed that the hedge fund was actually betting that the so-called synthetic securities would default, the suit said.

Goldman initially bet on the failure of the underlying bonds in the deal, but secretly sold its position to Paulson.

Once the SEC settled that lawsuit, many believed that Goldman got off with very little consequences. But you can envision more lawsuits of the type of ACA. The SEC suits set aside $250 million for investors, but ACA obviously felt their share of that would not be enough. They are seeking $120 million in damages, almost half the pool.

This is a pinprick for Goldman, but if it becomes a trend, you have something more serious.