US mum Stephanie Lenz filmed her toddler dancing to the Prince song "Let's Go Crazy" and posted the clip on YouTube for family and friends to see.

The video was removed after YouTube received a takedown notice from Universal Music Publishing, the company with the rights to publish the song, on the basis that the use of the song in the video infringed US copyright law. The purpose of copyright law is to ensure that persons who produce work retain control of it and benefit from its use. The exception to this is the concept of 'fair use' in the US and 'fair dealing' in the UK which allows, for example, use of material for the purposes of criticism, review and news reporting. It must be noted, however, that the US concept of 'fair use' is much broader than the UK equivalent.

Ms Lenz then raised a court action against Universal Music Publishing as she believed that her use of the song was 'fair use'. She argued that Universal ought to have checked whether the video was 'fair use' before demanding that it be removed. The Judge found in favour of Ms Lenz and the video was later reinstated on YouTube.

Ms Lenz also claimed damages from Universal. While the Judge agreed that she could recover legal fees for raising the action to have the video reinstated, he did not agree that damages should be awarded.

The result of this decision is that copyright holders must first determine whether material falls under the exception of 'fair use' ('fair dealing'), before demanding that it be removed from the internet. If companies fail to do so, they may face an increasing number of court battles and if they lose, they may also be landed with the expense of the action.