T-Mobile has been sued for losing Sidekick users' data, despite the fact that the incident was caused by Microsoft's Danger subsidiary.
Two separate class-action lawsuits allege that T-Mobile misled consumers into believing that their data was secure.
Sidekick user Maureen Thompson asserted in a lawsuit filed in a federal district court in California that one of the major selling points of Sidekick was that users always had access to their personal data, and that such data would be entrusted to T-Mobile to maintain and retain safely and securely.
Thompson claims that she "suffered a complete and catastrophic loss of all data", including appointments and contacts. Her daughter, an aspiring model and singer-songwriter, lost her own photos and lyrics that she had stored on the device.
Thompson's lawyer claims that Thompson and her daughter chose Sidekick to avoid the very scenario that occurred.
The other lawsuit was filed in a Washington state court by Oren Rosenthal, who claims that T-Mobile's advertising did not disclose that the firm had no backup to ensure that customers' stored data could be retrieved if there was a failure.
T-Mobile is confident that it will get most of the data back, and is offering $US100 vouchers to those who lost information.
Microsoft has now said that most, if not all, data affected by the recent outage is retrievable. The company plans to start restoring the data as soon as possible, starting with personal contacts, after it has validated the data and its restoration plan.
A spokesperson said that Microsoft will work around the clock to restore data to all affected users, including calendars, notes, tasks, photographs and high scores, as quickly as possible.
Microsoft also claims that only a minority of Sidekick users have suffered data loss.