We do have a law on the books saying porn distributors must do due diligence w.r.t. verifying that the people featured in their material are of age. One of the reasons why is because Traci Lords lied about her age to the production company, and actually appeared underage in all her movies but one. It got the company in a shitton of trouble and the Feds made them remove her tapes from circulation and destroy any extant copies, lest they be slapped with child porn charges.