And who said it would? Who even said only a virus could attack you?
I've got a mini-CD with a Linux distro on it that I can use in any computer when I want to surf the web or FReep. Nothing is mounted writeable, and the machine performs the exact function I want.
So what, you'd still be suceptable to direct attack of any unpatched vulnerability that could corrupt or interfere with your session. You're simply relying on the unlikeliness of FR being compromised or your IP being directly attacked.
"So what, you'd still be suceptable to direct attack of any unpatched vulnerability that could corrupt or interfere with your session."
Oh, no! You mean a WHOLE SESSION? Egads, man! That means I'd have to REBOOT! The horror!