Cryptocurrency is largely unregulated and decentralized, however, some countries have taken steps to regulate or ban cryptocurrency activity. In the US, for example, the SEC (Securities and Exchange Commission) has issued guidance warning investors against investing in cryptocurrency due to the lack of regulation. Other countries, such as Japan and South Korea, have implemented more stringent regulations on cryptocurrency exchanges, requiring them to register with the government and follow strict anti-money laundering rules. It is also worth noting that different countries have different regulations and policies when it comes to taxation and other financial issues related to cryptocurrency transactions.