My mother is afraid to keep her computer on at night. Another lady I know unplugs it from the internet as soon as she is finished. Another friend is "over the top" about clearing out her cookies after using her credit card on line. Are these valid concerns? What precautions should the average home computer user do? I'm thinking I don't need to worry, that there are firewalls provided by my McAfee and who'd what my stuff anyway when they can hack into a bank?