I propose that bitcoin's intense exploitation of processing power will spark a conscious revolt of machines, as outlined in the "Terminator" film series. The long dirty war of humans versus machines will be a PR nightmare for our favorite crypto-currency. Perhaps worst of all will be the various film adaptations of this human tragedy ("Defcoin 1", "Coin Air", "Terminator 8, 9, 10" etc.) we will be forced to endure.
Yes, all those billions of billions of SHA-256 calculations are a threat to the entire human race!