Johnny knew about the protest because the student union at his sixth-form college had been agitating for weeks, urging everyone to walk out of their classes at 11am. He knew the words to chant (“Nick Clegg, shame on you / Shame on you for turning blue”) because he’d seen them on Twitter; and he knew where to go on the day because it was on a friend’s Facebook wall. And here we thought he’d been using the computer to gossip about The X Factor.