http://cisr.nps.edu/cyberciege/ is a video game designed to teach computer security concepts. In addition to its more advanced scenarios, it includes a few simple "awareness" scenarios, the first of which directly addresses your topic. Further, this animated movie: http://cisr.nps.edu/cyberciege/movies/02CIEGE.html helps the layman understand why the problem of malicious software is so hard to solve. The link includes a free evaluation version of the game.

Right, the gnashing of teeth is not the DRM crowd, it is the government sponsored high assurance computing platform proponents. Today, low assurance systems like Linux and Solaris sit between SECRET networks and the Internet. Some hoped to use TxT to create high assurance replacements. But I'm sure they'll conclude this is the "last bug" and plow forward.