Apple deleted songs from users’ iPods that were downloaded from music stores that competed with iTunes, say plaintiffs’ attorneys in the iTunes antitrust case happening today in Oakland, California.

Attorney Patrick Coughlin a jury in the U.S. District Court that Apple gave users “the worst possible experience,” and attempted to “blow up” users’ music libraries. He says the practice took place between 2007 and 2009.

Here’s how Coughlin says Apple did it. A user would download music from a competing music service to their iPod. The user would then try to sync their iPod to their iTunes library. iTunes would then tell the user they needed to restore the iPod back to factory settings. After the user did that, the music from the rival shop would be gone.

Apple is defending itself against a decade-old class action suit alleging that it unfairly prevented iPod users from using non-Apple music services. Apple, the accusation goes, used a clever upgrade to the DRM software in iTunes to prevent iPod users from downloading music from Real Networks’ music store.

The accusation that Apple actually took actions to delete music from other stores, however, is a new development in the case.

Since DRM doesn’t exist at iTunes any more, the result of the trial can have no impact on today’s technology. However, Apple could lose $350 million if it’s found guilty in the case.

Get more stories like this on TwitterFacebook