They should regulate Bitcoin to prevent money laundering. Decentralized doesn't always mean ignoring safety because of its anonymous system. Honestly, I don't think Bitcoin should be treated as a threat because its influence to financial system is not really that strong and worrying.The government will impose tax and rules for a transaction made within fiat and cryptocurrency, also may be within cryptocurrencies. Not all countries may perform this task, but there are few countries that are already undergoing this process.