Over half of Apple’s iPhone applications leak user information without direct consent, according to a recent study co-authored by UCSB computer science professor Giovanni Vigna.

Of the 1,400 iPhone and iPod apps studied, approximately 750 disclosed the device’s unique identification number. A smaller percentage of these programs leak more detailed personal information including contacts and e-mail addresses.

According to Vigna, most leaked data was used to target advertising at individuals based on their phone habits. While the study concluded that there are no immediate security risks from most of the applications included in the study, Vigna said leaked information could lead to dangerous privacy violations.

“In general, as the use of smart phones becomes more and more ubiquitous, we will be able to use our phones for everything,” said Vigna, “This mobile device ID is just as unique and personal as a social security number.”

Researchers from UCSB, Vienna Institute of Technology and Northeastern University developed software to track how information was used in individual programs. The software flagged sensitive information and detected whether it was sent to a third party.

Apple’s current inspection process checks for security risks and ensures protection of user privacy. However, the details of this process have not been made public.