Well, I mean, you knew a lawsuit over the Facebook IPO was forthcoming. Unless the stock did gangbusters out of the chute (few do) then someone was going to feel screwed.
The claim that investors were misled is interesting, intriguing even, as is the fact that just a week before the formal offering, the asking price was tweaked up almost ten bucks a share. It certainly lends credence to the claim that the issuance was less than honest.
On the other hand, you'd have to be a fucking idiot to have bought Facebook on its opening trading.