A correction was made to this story. Read below for details.
It used to be that music fans believed cryptic messages about Satan or the death of a band member were hidden within rock albums.
Nowadays, the secrets buried in digital music are way too easy to find, according to the Electronic Frontier Foundation (EFF). The consumer watchdog group, which focuses on the Web, is taking issue with Apple's practice of embedding customer information within iTunes music.
Apple includes customer names and e-mail addresses within song files purchased from iTunes, according to Fred von Lohmann, an EFF attorney. Several tech blogs wrote about the embedded information this week after Apple launched iTunes Plus, a service that features music stripped of controversial copy-protection software.
Von Lohmann pointed out that data could easily be compromised if an iPod is lost or stolen.
"It's not as bad as losing a credit card number," von Lohmann said, "but it's still information that people wouldn't want floating around out there--especially without them knowing about it."
Apple hasn't said why the company would leave customer information exposed. But some observers have speculated that Apple is adding watermarks to music files. Watermarking describes the practice of inserting identifying information into digital files so they can be tracked. Privacy groups frown on such practices, but von Lohmann doubts that these were Apple's intentions.
Mike Goodman, a Yankee Group Research analyst, argued that watermarking is "certainly better than digital rights management.
"Watermarking does not treat the consumer like a criminal," Goodman said. "DRM is also restrictive, telling you how many times you can play a song or which device it can be played on. Watermarking works on the assumption that a consumer is innocent but provides the industry an opportunity to catch someone that breaks the law."
Ars Technica and Tuaw earlier reported on the personal information within iTunes' music.
Correction: This story erroneously reported that Apple had in the past encrypted personal information of iTunes customers embedded within music files. The data is available in clear text.