#Wikipedia knows many famous court cases. Adams v. Howerton is one of them. Another one is "Roe vs. Wade" it is even known by many people outside of the USA.
When you look at what Wikidata has to say about Adams v. Howerton, you will find that it is a bit sparse. When you look around, you will find that the text can be found on line: 673 F.2d 1036.
It is reasonable to expect that for all the US American court cases known to Wikidata the text will be available on line. It would be just a matter of defining the resource that does and, how the URL can be massaged to be be used in Wikidata.
People are expected to know and respect the law. It helps when it is easy for them to find pertinent resources.