The biggest lenders, Sallie Mae and Nelnet, are criticized by borrowers. They are frequently defendants in lawsuits, the most serious of which was filed in 2007. The False Claims Suit was filed on behalf of the federal government by former Department of Education researcher, Dr. Jon Oberg, against Sallie Mae, Nelnet, and other lenders. Oberg argued that the lenders overcharged the United States Government and defrauded taxpayers of over $22 million. In August 2010, Nelnet settled the lawsuit and paid $55 million. Ultimately seven lenders paid back taxpayer funds as a result of Oberg's lawsuits.