Rogue nations such as Iran, North Korea, and Venezuela are using Bitcoin and other cryptocurrencies to circumvent the sanctions placed on them by the United States and other nations. The inability to handle the diplomacies with dangerous dictators when cryptocurrencies become involved may pose a threat in the future to the market mainly because governments of nations like the United States may shut them down because they deem cryptocurrencies as a vehicle to fund terrorists or dictators like Kim Jung II and deem it as a threat to national security. I think currencies like Monero are most vulnerable to things like this as it is the leading candidate for being the black market coin of the future and may run foul with regulators at many different countries.