Soon after Xiaobo's death, the Chinese government lifted the restriction on WhatsApp, but the recent blockade is said to be related to the upcoming 19th National Congress of the Communist Party of China.
He said to the NYTimes that his company had been tracking disruptions of WhatsApp in China since last Wednesday, and that it efforts had become widespread by Monday.
China has, over the past few years, taken numerous measures to strengthen what is referred to as the Great Firewall, legislative edicts designed at controlling the use of internet services in the country. China has reinstated WhatsApp access after past disruptions.
"Essentially, it seems that what we initially monitored as censorship of WhatsApp's photo, video, and voice note sharing capabilities in July has now evolved to what appears to be consistent text messaging blocking and throttling across China".
WhatsApp users on worldwide SIM cards and data plans have not experienced the same problems.
With the ban on WhatsApp, China also bid adieu to all Facebook products, as the main social media service was banned as early as 2009, with subsequent curbs in other products placed later. Many consumers are embracing Chinese online services such as WeChat, which is similar to WhatsApp but easier for the government to monitor, and Weibo, a micro-blogging site similar to Twitter.
The Open Observatory of Network Interference (OONI), a global observation network for detecting censorship, surveillance and traffic manipulation, suggested that Chinese internet service providers started blocking access to WhatsApp on September 23.
Timothy Heath, senior worldwide defense research analyst at the RAND Corporation said that the Chinese government does not like strong encryption of WhatsApp.
WeChat is the most popular messaging app in China with over 600 million active users.