Censoring sensitive information is an authoritarian regime's best guarantee to prevent instability and challenges to its control over the population. China's censorship of information is enforced on all media and means of communication since the Communist Party takeover in 1949. Any information that might provoke public backlash is censored. China's Internet censorship is the most extensive and sophisticated in the world, with tens of thousands of "internet policemen" examining communications and content in real time and thousands of sites blocked. Despite the so-called "great firewall of China", Chinese are able to circumvent it using proxy servers and challenge the regime by reporting and discussing issues like corruption and human rights.