The hue and cry about the Library of Congress acquiring the Twitter archive, dating back to its origins in 2006, has shown that we continue to stubbornly believe two myths about social networking. First, that it is private. Second, that it is trivial.

Social-networking sites seem to have a curiously alcoholic effect on users. We approach cautiously and often cynically, then, as we find friends or followers, we gain enthusiasm, lose inhibition, and start taking risks. Just a few days ago a 22-year-old Australian student was expelled from his political party after he tweeted racist rubbish while watching Obama on local television. One tweet read: "If i wanted to see a monkey on TV id [sic] watch Wildlife Rescue." He said in his defense that his friends understood what he meant, and his tweets had been taken out of context. Which isn't particularly reassuring. Of course, he is not alone—there is an enormous amount of racist venom online, much of which, annoyingly, is anonymous. And yet it remains part of who we are—as do those who howl it down. (To all who hide behind code names: stop being cowards. Free speech is one thing; hiding behind a pseudonym to bait, goad, and spew bile is simply gutless.)