Machines get blamed for Dow's plunge

"Lightning-fast trading models, automated sell orders and an arsenal of sophisticated algorithms ... are likely to have made a crazy trading day that much crazier," the WashPost reports:

Why it matters: "The computers react to evidence exponentially faster than any human — think millionths of a second, instead of minutes — and can move en masse, trading at high volumes around the world. That makes them potentially ... dangerous."