There are dangerous trade-offs associated with new media. The influence of television -- popularized in the 1950s and in full swing in the 1960s -- reshaped the political and cultural landscape. The computer revolution hummed along quietly until the internet and desktop and laptop machines blended in the early 1990s to set off the phenomenon predicted at the advent of television by Canadian academic Marshall McLuhan. The medium, said McLuhan, would soon be the message, a famous statement that Woody Allen immortalized in the film Annie Hall. Medium Cool, a cult hit film of the 1960s, ensured McLuhan's permanent fame....