https://www.techdirt.com/articles/20210212/15192846238/content-moderation-case-study-valve-takes-hands-off-approach-to-porn-via-steam-2018.shtml

Summary: Different platforms have different rules regarding “adult” content, but they often prove difficult to enforce. Even the US judicial system has declared that there is no easy way to define pornography, leading to Justice Potter Stewart’s famous line, “I know it when I see it.”

Many, if not most, internet websites have rules regarding such adult content, and in 2017 Valve’s online game platform, Steam, started trying to get more serious about enforcing its rules, leading to some smaller independent games being banned from the platform. Over the next few months more and more games were removed, though some started pointing out that this policy and the removals were doing the most harm to independent game developers.