Most people don't have the slightest understanding of how the Internet works; for them, it is indistinguishable from magic. It would be nice if users understood how their machine fits into the Internet, how one computer communicates to another (at a high level, not necessarily the gritty details), and precisely what sort of hazards that subjects them to (and doesn't subject them to - e.g. everything that goes wrong on your machine is NOT necessarily the fault of a "virus").