] A source near T-Mobile's high level security teams
] has informed Gizmodo that the carrier has given an
] informal ultimatum to Danger, the company that produces
] the hit Sidekick and Sidekick II. The problem isn't
] the device itself, but the security of the backend
] servers, which Danger also manages. If the security
] issues plaguing the platform are not fixed, says our
] source, T-Mobile intends to stop selling the Sidekick.

Unconfirmed: T-Mobile Gives Danger Security Deadline : Gizmodo