are complaining that a Christmas update of their Google Nexus S phone wiped everything but the SIM. The update was supposed to improve the phone from 2.3 Android OS, to 2.3.1.
According to the Guardian after the install was finished all the settings - mail, camera, locations of icons, downloaded apps had been wiped. The problem may be because the Nexus S doesn't have separate storage but it means that all that money user's spent on Applications will be gone with the Wind.
Some are reporting that the update was OK for them and might be only a problem if people are rebooting in bootloader mode. Either way it might not be common fault but it might not be a good idea to update until the situation is a little clearer.