Linux is not in the public domain. Linux is a cancer that attaches itself in an intellectual property sense to everything it touches. That's the way that the license works.
Bio: Laurence Edward LeSueur was an American journalist, who was a war correspondent during World War II. He worked closely with Edward R. Murrow and was one of the original Murrow's Boys. He died in 2003 after a long battle with Parkinson's disease.