A service outage at the Microsoft subsidiary, Sidekick provider Danger, which led to a massive data failure earlier this week, has affected a large number of Sidekick users, who have permanently lost their personal information including contacts, calendar entries, and photographs.

According to a Saturday statement by the Microsoft subsidiary, while some of the T-Mobile Sidekick users saw data return during the week, the remaining users who still have their data missing on their devices have probably lost it forever.

Though users are urging Sidekick support forums to give them some guidelines for restoring the data on their devices, T-Mobile almost confirmed that the data loss was permanent, saying: “Our teams continue to work around-the-clock in hopes of discovering some way to recover this information. However, the likelihood of a successful outcome is extremely low.”

While both Microsoft and T-Mobile have refrained from disclosing the number of users affected and the amount of data lost, the data failure – which essentially is an embarrassment for both the companies - would likely blur Microsoft’s broader "software plus services" policy. 

Despite the fact that the Microsoft model is being pushed by many service providers as a safe and increasingly convenient way to handle data, the data failure questions about whether consumers and businesses can trust Microsoft to dependably store crucial data on their servers.