Government regulations banning certain things: toys, cribs, cars, foods, paints, medicines, etc... are for safety reasons not ethical or moral reasons. There is an implyed belief that what we put in our mouth, on or in our bodies, have our kids play with, vehicles we drive, etc... with will be safe and we will not be hurt physically or die from those things. Whereas porn (and books or movies that many would find to be "R" or "X" rated), while offensive to many- including myself - in and of themselves can't physically harm you - unless you get a paper cut - like the lead paint in a childs toy which has been banned.