Correct, that was decided in a court case in the US. I'm not sure that was a good decision, but you are right that is the legal precedent.
But that case was about pornography; there is no allegation that TikTok is pornography, only that is addictive. Who is going to be next? Is my or your Lemmy instance admin going to be sued because people like using Lemmy too much and one of its users or a government claims that it's addictive? You can see why that thought process is dangerous for the entire free and open Internet.
Freedom of speech covers all government action, including by the judicial branch by holding people or organizations liable for speech.
