In other words, to paraphrase Harvard professor Jonathan Zittrain, the 2000 presidential election—where George W. Bush won Florida by 537 votes—could have been altered by a Facebook election button.
But in order to do these kinds of experiments, Facebook has to create a control group—which means only showing the button to some users, and not to others. In 2012, Facebook said that it would make the button available to every user, as a kind-hearted effort to increase voting all around. Except that it never actually did, and instead continued the testing. As revealed by Micah Sifry in a feature at Mother Jones last week, the 2012 election button played host to many experiments: