There are a lot of comments here suggesting that this case is cut-and-dried obvious. YouTube is a private entity, QED. This case is more nuanced than that, and

There are a lot of comments here suggesting that this case is cut-and-dried obvious. YouTube is a private entity, QED. This case is more nuanced than that, and part of an ongoing, evolving understanding of the purview of the First Amendment in the United States. (NOTE: IANAL, much less a constitutional law scholar, I'm just digging into some news over coffee as an interested citizen) Poking around the case materials a little bit: PragerU lawyers reference a decision (here: https://caselaw.findlaw.com/us-9th-circuit/1332974.html https://caselaw.findlaw.com/us-9th-circuit/1332974.html) in which a corporate entity tried to remove street preachers from grounds (the Rose Garden) partially leased from a public entity (the City of Portland). The court found in favor of the preachers, holding that the corporation effectively was a state actor over which the court had jurisdiction. If you read the reasoning in that case, you'll find reference to other cases in which the courts tried (unsuccessfully) to hammer down what counts as a state actor. From a very cursory reading there's substantial jurisprudential churn around the notion of "state actor" - there are commonly accepted "tests" (which are sort of like thought experiments in philosophy), a substantial amount of common sense, and a large margin of error involved in determining whether or not a private entity is behaving in a way that might run afoul of restrictions placed on public actors. It's clear that there are cases where publicly owned resources are leased to private entities, and that "speech" happens over these resources (broadcast frequencies, ISP rights, publicly-owned domains, etc.). There certainly are private actors in this space that do fall under the purview of the First Ammendment. Again, I don't think YouTube is such an entity - and the courts agree - but this is a space where limits are evolving and being tested all the time. edit: I enjoy the court's somewhat punchy decision: Both sides say that the sky will fall if we do not adopt their position. PragerU prophesizes living under the tyranny of big-tech, possessing the power to censor any speech it does not like. YouTube and several amicus curiae, on the other hand, foretell the undoing of the Internet if online speech is regulated. While these arguments have interesting and important roles to play in policy discussions concerning the future of the Internet, they do not figure into our straightforward application of the First Amendment. Because the state action doctrine precludes constitutional scrutiny of YouTube's content moderation pursuant to its Terms of Service and Community Guidelines, we affirm the district court's dismissal of PragerU's First Amendment claim.