• by Laurie Sullivan  @lauriesullivan, January 24, 2019

Microsoft confirmed late Wednesday that its search engine Bing has been blocked from serving up in China, but a source in the country told "Search Marketing Daily" he can access the search engine from his home in Shanghai.

China has tightened control around the type of news that citizens within the country can see, but a quick search on cn.bing.com from within the United States continues to work.

At the World Economic Forum in Davos, Switzerland, Microsoft did confirm  that the engine had been blocked in China. On Thursday the company said the search engine now works in China, but company executives are working to determine exactly why this happened.

Online news sites in China have been required for years to have a government license to publish news on the web and social media, but Microsoft Bing has managed to operate in the country.

Services like Google, Facebook and Twitter have been blocked for years. Google Search has been blocked in China since 2010, and in December Sundar Pichai, the company’s CEO, said Google has no plans to relaunch a search engine there.

Bing had been banned using a domain-name system (DNS) corruption, a method used to block websites in China, TechCrunch reports. It means Chinese name servers are unable to retrieve the IP address of a URL. Some people have been able to access Bing by directly typing in the IP address.

As of two weeks ago, LinkedIn was required to verify people using a Chinese IP address to link a mobile phone number to their account as part of a name verification process.

In a statement on Wednesday, reports Reuters, the Cyberspace Administration in China said it deleted more than 7 million pieces of online information and 9,382 mobile apps. And it criticized technology company Tencent’s news app for spreading vulgar information.

Baidu -- which controls about 76% of the market share in China -- is the most popular search engine in the country, per Wikipedia, and now operates under strict guidelines until Chinese law. Sogou follows, along with SO.com, Youdao, and Shenma.