An anonymous reader shares a report: A Chinese man has been given a nine-month jail sentence for helping people evade government controls on where they can go online. Deng Jiewei, from Guangdong, was charged with illegally selling programs known as virtual private networks (VPNs), according to court papers. VPNs are illegal in China because they let people avoid government monitoring of what they are doing. The sentence is part of a larger crackdown on the use of VPNs in China. Deng started selling VPNs in late 2015 and was arrested in August 2016 for selling software which lets users "visit foreign websites that could not be accessed by a mainland IP address," reported the South China Morning Post. The Chinese government operates a massive monitoring system, known as the "great firewall," that watches what people do and say online. It also blocks access to sites, such as Facebook and YouTube, that are popular outside the country.