You'll be fascinated by this article. In essence, Universal Music went after a mother who posted a 30-second video on YouTube of her baby dancing to some music by Prince. They evidently went after the wrong mother--cause she sued them.
The federal judge said the lawsuit may proceed, because the copyright holder (Universal Music) must consider fair use before sending out their standard cease-and-desist letter.
I have one question...
What is Universal Music thinking? A mom loves your music, and her baby really loves your music. It makes mom so happy that she shares it with the world. And you come after her threatening to take legal action? Are you serious?