In the past year, securities class-action lawsuits have risen by 43%. 

2007 saw 166 of them, according to a joint study by Stanford Law School and Cornerstone Research due for release shortly.

With a ten-year average of 186 cases per year (not including this year) 2007 is hardly a spike.  The late 1990s were hectic, with 200+ cased filed in some years.  Lately though, with the stock market relatively stable and with stronger regulatory oversight of corporate governance, things were looking better.

The subprime mortgage market caused a large portion of the recent increase in cases, with 32 class-actions having been filed this year.  It's all about mortgages based on improperly inflated appraisals, and the outlook is grim. 

It is unclear whether we've seen the peak of subprime filings, or whether securities class-actions are back for good.  Only time will tell in both cases.