Media reports suggest that the DRM-free song files collect and store the iTunes account information of the users who purchased the titles.
The site claimed that pulling up the song data reveals the first and last name of the buyer, along with the email address which serves as a user ID.
Other users have reported that the data can be viewed simply by selecting the 'get info' option on the song file.
Spokespersons for Apple could not provide confirmation or official comment at the time of publication.
The revelation could put a dampener on what many advocacy groups had hailed as a victory for consumer rights when Apple announced that it would be providing tracks from EMI without DRM software.
Cotton seedling freezes to death as Chang'e-4 shuts down for the Moon's 14-day lunar night
Fortnite easily out-earns PUBG, Assassin's Creed Odyssey and Red Dead Redemption 2 in 2018
Meteor showers as a service will be visible for about 100 kilometres in all directions
Saturn's rings only formed in the past 100 million years, suggests analysis of Cassini space probe data
New findings contradict conventional belief that Saturn's rings were formed along with the planet about 4.5 billion years ago