Oh, THAT kind of risk. This level of computing wont be available for a while if at all for consumers. At least for now, If there is anyone out there cracking encryption with quantum computing technology today though, it should be easy enough to track down who the culprit is. Even if QC ever became truly widespread, something like hacking Blockchains would no doubt take a minimum of technical skill level and won't be something just anyone can do. I suspect we could have some people cloning coins similar to how today someone could use their iphone or other means to detail your magic stripe on your credit card. A smart man once told me that any "Money" needs to be backed by something else of value else it's worthless. Maybe the powers that be had it right all along with their bills and coins and bullion? I'd like to see a quantum computer decrypt one of those :)