A Texas anti-pornography law is going before the Supreme Court on Wednesday in a collision of free speech rights, regulation of online content and the protection of children.

Texas is among more than a dozen states with similar laws aimed at blocking young children and teenagers from viewing pornography. The adult-content site Pornhub has stopped operating altogether in several of those states, citing the technical and privacy hurdles in complying with the laws.

Texas says its measure is necessary to protect children from the current near-instantaneous access to porn, including hardcore obscene material, on smartphones. “Texas seeks to protect kids from some of the most prurient sexual content imaginable,” state attorneys wrote in court documents.

The Free Speech Coalition, an adult-entertainment industry trade group, says the Texas law wrongly affects adults by requiring them to submit personal identifying information online, making it vulnerable to hacking or tracking.