Alternatively, FB may just want to keep financials a secret because they are worth a lot more when people are wildly speculating than they would be if they had to be as open as a public company.
(Goldman probably got a look under the hood, but I doubt they will pass that along to the investors they hope to sell Facebook investments to, so both FB and Goldman will benefit from uninformed speculation.)
Any prospectus put together by Goldman will have significant disclosure and results of their internal audits. Despite the hoopla, this is a pretty regulated area of commerce.
As to who will read such a prospectus, that's likely a different beast altogether.
It's my belief that FB is more likely to be in a pre-IPO Google situation right now, that is, that they're sitting on more than people realize, not less. I recall Google routinely requiring academics to cut the server and request numbers by a factor of 10-100x when giving talks about what was going on, pre-IPO. A luxury I'm sure they would appreciate still having.
(Goldman probably got a look under the hood, but I doubt they will pass that along to the investors they hope to sell Facebook investments to, so both FB and Goldman will benefit from uninformed speculation.)