Although the market for earnings restatements is robust (over 1,200 last year alone), the NY Times Steve Labaton reports that the market for lawsuits based on those restatements is not:

For all of the handwringing in some corners of Washington and in corporate America about vexatious litigation, it turns out that you can count last year’s number of investor class-action lawsuits against accounting firms on one hand.
A mere five cases were filed, according to the tally produced each year by Prof. Joseph A. Grundfest of Stanford Law School, a former commissioner at the Securities and Exchange Commission. The report found a sharp decline in the overall number of securities fraud class actions, as well as a marked reduction in the investor losses claimed by the suits. And it found that the Ninth Circuit, which includes California, a traditional haven for lawsuits because of the large number of technology start-ups, has been “losing its prominence.”
What’s going on?
Professor Grundfest, who has often been critical of what he sees as baseless shareholder litigation, has two explanations. The lawsuits related to the bursting of the market bubble beginning in 2000 are now largely over.
“The pig may have moved through the python,” he said.

The article goes on to note other chilling effects on the class action business fraud lawsuit, such as increasingly pro-business jurists, SOX (not sure about that one), the PSLRA, and the Supreme Court’s Dura decision.