If sensitive information is stored on your hard drive (and if you don’t have -something- worth protecting on your system, you’re probably not reading this blog…), protect it with encryption.
Furthermore, when you copy or move data elsewhere, it’s usually at least as important to protect/encrypt it when it’s on removable media, or transferred electronically. Even if the target storage device is secure from malware or hacking, you also need to be aware of other dangers such as physical risks, transit risks, business-related risks such as an escrow site going out of business and so on.
Consider (seriousl!) regularly backing up your data to a separate disk (as a bare minimum) and, where possible, a remote site or facility. Sounds extreme? Think about it.
You can’t rely on backing up to another partition on the same disk as the original: if the disk dies, the chances are that all partitions will be lost.
You can’t rely on backing up to another disk on the same system. If the system is stolen, or there’s a fire, for instance, then in the immortal words of Tom Lehrer they’ll "all go together". In the latter instance, the chances are that you’ll lose your thumb drives, CD-RWs and so on as well.
And if you’re working in a corporate environment, you might want to avoid doing what one site I know of did, and back up data to a server, but forget to back up the server itself.
I’m sure I don’t need to remind you to take care of your passwords as well, do I?
David Harley BA CISSP FBCS CITP