This has been revisited multiple times since then and guess what? Free speech/expression DOES include this little bit here. Don't know if you noticed but there's a whole industry based on this that makes billions every year.
The adult industry has skated by in that sense, much of it can be prosecuted actually. The state just has chosen not to enforce the laws.
I can tell you that much of the porn out there can be considered obscene. Especially websites that host and distribute pornography that
has no dialog. And especially websites/blogs that distribute pornography to which they have no rights to and no 2257 documentation on file
proving the age of the model and model releases/contracts
And what is obscene is decided by "community standards"
Which is why when you read about an obscenity trial you often see details like Company X shipped material to very conservative State X
In Florida for example, Lakeland is extremely conservative and does not allow even Playboy magazines to be distributed
there have been several cases tried there, and started there because its almost guaranteed residents would go against porn
Hence why many companies won't ship adult materials to certain zip codes
There's the famous 'Cambria list', named after its creator Paul Cambria that spells out what not to do in order to stay compliant with obscenity laws.
Theoretically anything that falls in the Cambria list can be prosecuted and get convictions on