According to this LA Times article:
Joe Francis and the Santa Monica-based company he built on soft-core “Girls Gone Wild” videos pleaded guilty Tuesday to violating federal laws designed to prevent the sexual exploitation of children and agreed to pay fines totaling $2.1 million.
Under the terms of a deal with the Justice Department, Francis agreed to personally pay a $500,000 fine to settle charges in Los Angeles that he failed to keep records of the ages and identities of the women who appeared in his films. As a result, Francis said in a statement, footage of minors engaging in sexually explicit conduct appeared in at least two DVDs he released.
Via Culture Kitchen.