Most people don't intentionally distribute a virus. Some of them slip through, though, and are UNintentionally distributed. For instance, my sister, running Norton, was taken down by a virus a year or two ago. When she got back up, she had to re-upload parts of her website. Why? I don't remember the details, but the virus exploited some Microsoft bugs and attached itself to every HTML file on her system as a malicious script. Some of those HTML files were then unknowingly loaded up to her site, where they could spread to her visitors. I would hate to see my beloved sister punished with heavy fines and jail time because she was an unfortunate victim. The point is, a virus can get in without anyone knowing it. Viruses have been found on shrink-wrapped CDs bought from major software companies. They're just insidious buggers.