Arizona today joins about two dozen states that require age verification to access porn websites.
Why it matters: Age verification laws are meant to prevent people under age 18 from accessing pornographic websites.
But free speech advocates say such rules could infringe on adults' First Amendment rights.
Catch up quick: The U.S. Supreme Court ruled this summer that laws mandating age verification on adult sites doesn't violate the First Amendment.
The latest:Pornhub announced it will go dark in Arizona starting today because of the new law. The website has stopped operating in more than 20 other states because of similar laws.
What we're watching: Virginia was one of the first states to adopt age verification in 2023, but a recent review by Axios Richmond found that many sites are still widely accessible without age checks in the state.