Fruity cargo cult Apple deleted music from its customers’ devices which were not bought through the iTunes Music Store.

The information has come out of the proceedings of Apple’s iPod/iTunes antitrust lawsuit. Plaintiffs’ lawyers claimed Apple surreptitiously deleted songs not purchased through the iTunes Music Store from users’ iPods.

If this is true then the order must have come from Steve Jobs himself.

Attorney Patrick Coughlin, representing a class of individuals and businesses, said Apple intentionally wiped songs downloaded from competing services when users performed a sync with their iTunes library.

Users attempting to synchronise an iPod with an iTunes library containing music from a rival service, such as RealNetworks, would see an ambiguous error message without prompting them to perform a factory reset. After restoring the device, users would find all non-iTunes music had disappeared.

The court was told that that Apple decided to give its users the worst possible experience and blow up,” the iTunes library, Coughlin said.

Coughlin claims that Apple manufactured the error message in a move to stop customers from using their iPod to play back music from stores other than iTunes.

Apple insists that the system was a safety measure installed to protect users. Apple security director Augustin Farrugia said additional detail about the error’s nature was not necessary because, “We don’t need to give users too much information,” and “We don’t want to confuse users.” He went on to say that Apple was “very paranoid” in its protection of iTunes, a sentiment echoed in an executive email penned by Steve Jobs in 2004.

Jobs’ emails and a videotaped deposition revealed Apple was “very scared” of breaking contractual sales agreements with music labels, which in turn prompted an increased interest in digital rights management (DRM). Although iTunes no longer sells DRM-protected content, Jobs said frequent iTunes updates were needed to protect as “hackers” found new workarounds.

The case said that Apple is accused of creating a monopoly locking users into a closed ecosystem with FairPlay digital rights management (DRM), the iPod and the iTunes Music Store. Plaintiffs are seeking $350 million in damages, an amount that could be tripled to over $1 billion under U.S. antitrust laws.

Aside from Jobs’ deposition, current Apple execs Eddy Cue and Phil Schiller are scheduled to testify later this week.