Some of those laws do seem insane, but some are a must. An example would be Florida. I would hope all states have that law, as otherwise... selling children would not be illegal. If there isn't a law saying something is illegal, it is therefore legal.
@Harry Havens ...geez i should think common sense would prevail over that...but apparently not in Florida
Our entire legal system is based on English law. In English law... "Everything which is not forbidden, is allowed." The 9th and 10th Amendments embody that principle. Having said that, it is also a federal crime. https://www.law.cornell.edu/uscode/text/18/2251A It is sad that such laws are necessary, but without them...!!!!