A producer of online civics lessons with a conservative bent got schooled by a federal judge on why it's hard to sue Google for censorship.

The U.S. Constitution's First Amendment bars the government from silencing people over their political views, but it doesn't require private companies to be free speech zones.

U.S. District Judge Lucy Koh dismissed a lawsuit accusing YouTube of illegally restricting access to dozens of short videos on public affairs topics produced by Prager University, a nonprofit started by conservative radio talk show host Dennis Prager. A filter that YouTube says is used to protect young, sensitive viewers from inappropriate content is actually "a political gag mechanism to silence PragerU," the nonprofit said in its complaint.