Danger, the Microsoft-owned company which produces the T-Mobile Sidekick, has admitted that it's managed to lose every single scrap of data that was being held on its servers. For good. Everything. Contacts, calendars, photos, to-do lists - if they're not locally backed up on your device then they're gone.

Even if you do have it saved on your device, if it runs out of battery or you turn it off before you sync it up again with the servers then it'll be gone too. Worst of all, the data loss appears to have occurred because no-one thought to take a backup of the data before Microsoft undertook an upgrade of its storage systems.

T-Mobile, Microsoft and Danger have jointly issued an apology to customers, saying: "Based on Microsoft/Danger’s latest recovery assessment of their systems, we must now inform you that personal information stored on your device – such as contacts, calendar entries, to-do lists or photos – that is no longer on your Sidekick almost certainly has been lost as a result of a server failure at Microsoft/Danger".

Affected customers are likely to be offered some sort of compensation - "We recognize the magnitude of this inconvenience. Our primary efforts have been focused on restoring our customers’ personal content. We also are considering additional measures for those of you who have lost your content to help reinforce how valuable you are as a T-Mobile customer".

If you've been affected by the data loss, we'd like to hear from you. Drop a comment below, or use our feedback box to tell us your experiences.