Citigroup has begun notifying some 3.9 million U.S. customers that computer tapes containing information about their accounts have been lost by United Parcel Service (nyse: UPS - news - people ) while in transit to a credit bureau.

FORBES

The organizations include the CERT Coordination Center, the Electricity Sector Information Sharing and Analysis Center, the European Cyber Crime Center, the Malaysia Computer Emergency Response Team, the Australian Federal Police and the Irish Reporting and Information Security Service.

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Computer security experts have warned users to be careful over how much personal information they share on the service, and to consider carefully their privacy settings.

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