But he said that some WhatsApp users might still be able to use the service. The Chinese authorities have a history of mostly, but not entirely, blocking internet services, as well as slowing them down so much that they become useless. When China joined the World Trade Organization in 2001, it agreed to open online data services and other enhanced telecommunications services to international competition. WhatsApp has a strong reputation among cryptographers for security, which may have been what drew the attention of Chinese censors. WhatsApp’s video, file sharing and other advanced features rely partly on broadly used internet data transfer protocols, and were disrupted over the summer.

Source: New York Times September 25, 2017 15:55 UTC