Apple Computer Inc., which has been criticized for gathering personal user information from its iTunes MiniStore, has added a new feature -- a warning telling users that personal information based on the contents of their music libraries is sent to Apple.

The MiniStore, part of the latest version of the iTunes music store, displays a bottom pane that shows artists and music titles a person may be interested in buying, based on the songs they selected in their personal music library. According to a posting on the Boing Boing blog directory, the store transmitted to Apple information related to users' listening habits, as well as their unique Apple identifier that's tied to their credit card, mother's maiden name and other personal information.

The disclosure brought criticism from privacy advocates, who objected to Apple not making it clear to users that it was gathering personal data, and not asking permission first.

"Allowing users to upload information voluntarily and expressly with adequate privacy protections is pro-user; surreptitiously siphoning it into a remote database without any privacy guarantees is not. It's time for Apple to pick a side of the line and walk it," Electronic Frontier Foundation wrote on its Web site.

Apple has since changed the MiniStore, found in iTunes 6.0.2, so when users turn on the feature they first receive a warning that information is sent to Apple, and are given the option to continue or to abort. No data is sent when the feature is turned off.

"As you select items in your library, information about that item is sent to Apple and the MiniStore will show you related songs or video," the warning said in part. "Apple does not keep any information related to the contents of your music library."

In a statement released late Wednesday, Apple acknowledged the change.

"We listen to our users and made access to the MiniStore and opt-in feature," the company said. "Apple did not keep any information related to the contents of our users' music libraries."

Privacy rights are a growing issue among online consumers and Internet retailers. The former want control over the handling of their personal data, while the latter is looking to gather as much buyer-related information as possible in order to improve their Web sites and target visitors with ads on products they are likely to buy.

Consumers fears over privacy has increased along with media reports of threats posed by viruses, identity thieves and phishers.

Almost a quarter of the 150.8 million online households in the United States use aggressive anti-spyware applications to remove cookies embedded in visitors' browsers to track their activity on a retailer's Web site or on the Internet, according to JupiterResearch.