iPhone that -- for the moment, anyway -- requires a jailbroken handset to run. It goes about its business on WiFi airwaves, so from the carrier's perspective, no harm, no foul, right? Not so much. T-Mobile Germany takes issue with the app, claiming that it's enticing its iPhone users to jailbreak -- a violation of its contract terms. Furthermore, the contract disallows VoIP of any kind, WiFI or otherwise, which pretty much makes sipgate public enemy number one in T-Mob's eyes. They've gone ahead and sent out a nasty little cease 'n desist, which sipgate says it plans to fight all the way through the court system if that's how T-Mobile wants to roll; meanwhile, it's still providing service and says that "for the time being [its] users are safe." Fight the good fight, guys.