A trial involving Apple’s DRM (Digital Rights Management) for its iTunes Music store is set to be in session today. As weird as it sounds, Steve Jobs is to give testimony.

Though the iPod is now considered largely irrelevant in the area of mobile tech, having been displaced by the smartphone in the pocket, the case goes all the way back to 2005. The plaintiffs are two consumers who bought iPods; buying and downloading music directly from Apple. The argument is that they ended up paying more than if Apple hadn’t violated antitrust regulations. The plaintiffs say they “suffered injury” (not literally of course) “in the form of overcharges”.

Locking users into its service meant that demand for iPods increased, as listeners had a vested interest in holding onto their music libraries. This meant that Apple could drive prices up, resulting in higher profits and angry consumers – who found out they couldn’t listen to their tracks on other MP3 players.

Part of an email from Jobs sent in 2003 to Apple executives:

“We need to make sure that when Music Match launches their download music store they cannot use iPod. Is this going to be an issue?

Apple claims that its DRM measures for iTunes were put in place because of demands from music labels, and so that they could make the user experience more secure. Though it’s a drop in the ocean to a company that made $8.5 billion in profit last quarter, the plaintiffs are seeking $350 million in damages.

This isn’t the first time that Steve Jobs’ email correspondence has been used against Apple in the courts. Last week, a settlement was reached over raised ebook prices. Emails were used as key evidence in that lawsuit.

If consumers bought an iPod directly from Apple between the specified dates in 2006 and 2009, then the lawsuit may actually affect them. Other than that, it’s a settling of old scores.