The success of market- and semi-market-based economies since then has made the notion of a planned economy seem like a thing of the past. But were a latter-day Allende to build a Cybersyn 2.0 it could now gather data via billions of sensors rather than a few telex machines, and crunch them in data centres packed with tens of thousands of servers. Given enough power, might it not replace the autonomous choices on which the market is based?