I think the only way to kill bitcoin is either to break SHA-256 (and that would probably be short-term) or aggressively shutdown the exchanges. As long as BTCs

I think the only way to kill bitcoin is either to break SHA-256 (and that would probably be short-term) or aggressively shutdown the exchanges. As long as BTCs are worth tens of thousands of dollars people are going to mine them. It's pretty hard for me to imagine that either of these things are going to happen. I don't think that cryptocurrencies are ever going to be really useful because they're so inefficient, but I also think that they're here to stay as a speculative/gambling tool. PaaS, pyramid schemes as a service.