From Apple’s Tiger Preview – Safari RSS page:
Safari protects your personal information on shared or public Macs when surfing the Web. Go ahead and check your bank account and .Mac email at the library or shop for birthday presents on the family Mac. Using Safari痴 new privacy feature, no information about where you visit on the Web, personal information you enter or pages you visit are saved or cached. It痴 as if you were never there.
Who guarantees that the Safari you see on that public computer hasn’t been changed? Who guarantees that there are no programs which sniff the keyboard, and the screen? Who guarantees that no hidden cameras are hidden in strategic places?Privacy features in some particular piece of software don’t mean that software is running in a trustworthy environment. Suggesting that users perform sensitive activities (such as banking) in untrusted environments, using untrusted computers, is terribly bad advice.