The Information Commissioner's Office (ICO) in the U.K. on Tuesday said that it had been approached by an unnamed mobile telephone service provider with information about employees believed to be selling customer data.
The data included mobile phone contract information and expiration dates.
In a statement on its Web site, T-Mobile said that it alerted the ICO when it learned that contract renewal information was being passed to third parties without its knowledge.
The mobile provider told the ICO that the information was being sold to competing service providers for lead generation: Competitors allegedly used the information to solicit T-Mobile customers whose contracts were about to expire.
"The customer information that was compromised contained no personal financial or security-related information whatsoever," the company said.
The ICO said that "substantial amounts of money have changed hands" and that a prosecution case is being prepared.
T-Mobile said it was "surprised" that its name had been publicly reported because it had been previously asked to keep all information about the incident confidential to avoid hindering the investigation and judicial proceedings.
"Whilst it is deeply regrettable that customer information has been misapproriated in this way, we have proactively supported the ICO to help stamp out what is a problem for the whole industry," said T-Mobile in its statement.
Information Commissioner Christopher Graham said that as more and more data is collected and as data collection systems become increasingly intertwined, the risk that such data may be abused will only increase.
"Many people will have wondered why and how they are being contacted by someone they do not know just before their existing phone contract is about to expire," said Graham in a statement. "We are considering the evidence with a view to prosecuting those responsible and I am keen to go much further and close down the entire unlawful industry in personal data."
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