Three years before the twin towers were destroyed, three months before Bill Clinton was impeached, two Silicon Valley entrepreneurs sent an email to a hundred of their friends, born out of their frustration at the way American political life had been hijacked by drawn-out attempts to remove Clinton. The email was a call to Congress to: 'Censure President Clinton and Move On to pressing issues facing the nation.' within days, thousands had signed the online petition. By the time Congress impeached Clinton in December 1998, the organisation spawned by that email had half a million members. Ten years later, more than five million people have signed up to MoveOn.org.