Last summer, Japan's Fuji Bank learned a hard lesson about the perils of computer viruses. It happened like this:
Looking to mobilize support for a proposed merger with two other Japanese banks, Fuji's public relations department fired off an email touting the deal to prospective investors around the world. Imagine the recipients' surprise, then, when they opened the pitch to read "You are a big stupid jerk" flashing on their computer screen. Now imagine their consternation upon discovering that opening Fuji's message also caused names in their email address book to change to "Mr. Diet Mountain Dew."