A horseshoe nail

The first and most important thing to remember about Tom Scott's five-minute Ignite lecture is that this is a work of fiction: the story he tells hasn't happened... yet. The second thing to remember is that the story he tells is based on real, relatively recent events: each piece leading up to the fictional climax of the story he tells is an event that did happen, somewhere, to someone. It's a remarkable, remarkable and chilling, account of how the posting of an idiotic video to YouTube leads to a flash mob leads to tragedy:

The funny thing about the world changing is that you don't always notice it at the time--no, that's wrong: you almost never notice it at the time; there, corrected. One day you're trundling along and it suddenly occurs to you that you can't remember the last time you saw something--a rotary dial phone or a set of rabbit ears antennae or a gas pump with a rolling analog dial or whatever. Or one day something happens--oh, hopefully it isn't a riot and a dead girl and blood in the streets--and you're not exactly surprised by it, that is, it's not that you knew it was going to happen in advance (you're not psychic) but the fact that it happened seems so ordinary and commonplace afterwards, that it was something that had to happen, that was inevitable and you can't feel shocked by it; almost a sense of déjà vu, indeed, I'm sure the French have some saying for it (they do for almost everything else).

Like Spider Robinson said in the quote Scott refers to in his first slide: the world turns upside down, but you turn upside down with it.

(H/t Boing Boing.)