To recover funds of failed banks. These law suits appear to hinge on establishing negligence on the part of bank directors in lending practices. From the NYT:
"as of mid-December it (the FDIC) had authorized lawsuits against 109 directors and officers of failed financial institutions in an effort to recover nearly $2.5 billion...The agency, which had to contend with 157 bank failures last year, may sue bank directors and officers for what it considers gross or simple negligence....Two bank suits, naming 15 people, have already been filed, the agency said, along with four authorized for fidelity bond and attorney malpractice, and 190 concerning residential malpractice and mortgage fraud....In November, the F.D.I.C. sued 11 executives of Heritage Community Bank, based in Glenwood, Ill., seeking to recover $20 million...In a suit filed with the United States District Courtof Northern Illinois, the agency said: 'The Bank routinely financed C.R.E. projects — including speculative ones (i.e., projects without committed buyers or tenants) — without any meaningful analysis of their economic viability, and often with inadequate appraisals.' C.R.E. refers to commercial real estate."