You can pierce the corporate veil if there is willfull and intentional fraud. Doesn't always happen, but it's possible.
And what, compensate people with the stock of the company that was found to be willfully and intentionally defrauding them?
No, compensate people with the money of the stockholders. That's what piercing the veil means: culpable stockholders assets are no longer protected from liability.
piercing the veil usually applies to manager-owners, like S-corps.
If I invest in a corporation and the managers do something horrible, the managers could potentially be reached through the veil, but not the stockholders -- their only involvement was handing over money, so they had no wrongdoing.
Now, investors who are also decision-makers on the Board or maangement, that's another story.
It requires that the particular stockholders be actually culpable and involved in the fraud - fraud done by non-owning management would not allow to capture funds of non-managing investors.
What I'm saying is the culpable stockholders (Holmes being the primary one) have few assets.
They have taken in over $400,000,000 in investment, I'm sure there are more than a few bucks laying around.