The 9th Circuit won't rehear a case concerning a YouTube video of a toddler dancing to the Prince hit "Let's Go Crazy." Via: http://www.hollywoodreporter.com/thr-esq/dancing-baby-appeals-court-decision-876557
Do you upload videos to YouTube that include music?
Consider this - In this case, the 9th Circuit held that when you use a song that you don't own in your YouTube video, the owner of the song must consider whether your use of that song is protected by the Doctrine of Fair Use before they take action for copyright infringement.
When determining if it is fair to use something, one must consider:
1- the nature of the use (if it is for nonprofit or educational purposes, it is more likely to be fair use than if it is to make money),
2- the nature of the work itself (factual information is more likely to fall under fair use than creative works),
3- the amount and the significance of the work to be used (using a small portion as opposed to a large portion of the work is more likely fair use),
4- the effect of using the work on the market (if the copyright owners will lose money by another person using their work, that would not be fair use).
Not all factors need to be present to be fair use, but they are weighed in the determination.