When do i need to use factory reset on BLACKBERRY PlayBook?

Factory reset on BLACKBERRY PlayBook could be used in several cases:

when your device is malfunctioning (also with viruses hard to remove),
when you wish to clear the configuration and the settings of BLACKBERRY PlayBook to the default setting,
when you need more memory space on your device,
when you plan to sell your BLACKBERRY PlayBook and you wish to clear all your personal data,
when you just want to start using your device from scratch.