To our knowledge, Bitcoin has not been declared illegal in most countries. However, there are some countries (such as Argentina and Russia) that strictly prohibit foreign currency. Other countries (such as Thailand) restrict the licensing of certain currency entities such as Bitcoin exchanges. Policymakers from various countries are taking steps to provide regulations for individuals and businesses on how to integrate this new technology with the regulation of the formal financial system. For example, the Financial Crimes Enforcement Network (FinCEN), a bureau of the United States Department of the Treasury, publishes a freelance guide on how governments deal with certain activities related to virtual currencies.