The legal status of bitcoin varies substantially from country to country and is still undefined or changing in many of them. While some countries have explicitly allowed its use and trade, others have banned or restricted it. Likewise, various government agencies, departments, and courts have classified bitcoins differently. Regulations and bans that apply to bitcoin probably extend to similar cryptocurrency systems. In April 2013, Steven Strauss, a Harvard public policy professor, suggested that governments could outlaw bitcoin, and this possibility was mentioned again by a bitcoin investment vehicle in a July 2013 report to a regulator. However, the vast majority of nations have not done so as of 2014. It is illegal in Bangladesh, Bolivia, Ecuador and Russia.