I DOUBT THAT anyone with a child porn habit reads this space but it astounds me when people would open themselves to prosecution because of what they have on their hard drives. You can cloak your activities by following a few simple steps. If you live and work in a repressive regime, these steps would provide you an essential layer of protection. If your supervisor watches your e-mail or browsing histories, you can remove all trail of your actions. And if you're a terrorist who needs to avoid the snoops, you probably know all this already: encrypt files, use a proxy, store your cache on a password-protected removeable key, use secure e-mail, don't keep things on external servers.
Traveling Forever -- "How to protect yourself from Big Brother"