Why would somebody want to encrypt files on their hard drive, especially if there is nothing to hide? Privacy is one of the fundamental rights that people are, or should be, entitled to. Just because you have no incriminating files, or ground breaking research stored on your computer, does that give others the right to paw through it? Of course not.
Your private material should remain private – not because you have something that you need to keep away from prying eyes, the majority of us don’t, but because privacy is a basic right that is slowly being eroded by those who claim to be for us.