This article originally appeared on ABACUS China’s Great Firewall blocks a lot of foreign sites. But inside China, sites and apps are blocking each other too. Users found that their WeChat contacts cannot see links they shared from Haokan -- a short video app made by Baidu, according to Chinese media reports. Meet Baidu, China’s homegrown search engine Tencent responded by saying that Baidu’s Haokan had broken WeChat’s link sharing rules with “earning online” behavior. When we asked WeChat to clarify what that means, a spokesperson sent us a screenshot of Haokan, where the app says users will be rewarded by cash for getting other users to sign up. WeChat said to Chinese media that it’s against WeChat link sharing rules -- but the term “earning online”, or “Wangzhuan”, does not appear in WeChat’s external link regulation . Baidu posted a statement on Weibo saying that they’re “deeply sorry” about WeChat’s double standards, claiming that WeChat still allows similar behavior from its own Weishi short video app. WeChat has essentially become China’s mobile operating system , where people can find virtually all of their daily online services, but that’s largely for Tencent’s own ecosystem of services. Some of its rivals are walled off from the country’s biggest social network, giving Tencent tremendous power. WeChat, the app that does everything WeChat blocked Uber in 2015 because of its “malicious marketing”. Coincidentally, or perhaps not, Tencent backed Uber’s big rival Didi. In the same year, it blocked music sharing from music apps including NetEase Cloud Music and Alibaba’s Xiami Music, which Tencent said at the time was because of music piracy. In a statement, NetEase hinted that it’s more due to competition. “We have no reason to complain -- it’s their (Tencent’s) turf afterall. They have their own music apps, and they don’t want to lose market share,” WeChat removed the ban in 2016. WeChat has also repeatedly blocked links from TikTok, the globally popular short video app made by viral content king Bytedance. Tencent’s argument is that it filters out links that appears too many times in WeChat Moments, so that users don’t have see the same content over and over again. As a solution, TikTok saves a video you want to share to WeChat to your local album, so that you can manually upload the video, with a TikTok watermark, to WeChat. Alibaba’s Taobao faces the same ban from WeChat when users want to share an item with their WeChat friends. Taobao has also been trying to make it easier: After you click “Share to WeChat”, it generates a link for the item you want to share, automatically copies the link, and opens WeChat for you -- so that you can then select a chat window, paste the link and send. It’s not nearly as slick as how sharing normally works, but it’s one way around it. (Abacus is a unit of the South China Morning Post, which is owned by Alibaba.) But WeChat is not the only one. While China’s tech giants each have their specialties, as they expand they’re encroaching on each other’s turf -- a natural consequence of their ambition to do everything, according to the 2018 China Internet Report. China Internet Report 2018 In 2013, Alibaba banned its sellers from using WeChat, citing too many promotional WeChat messages. That started a battle between the two giants, and in 2015 WeChat forced Alipay off its platform during Chinese New Year, when millions of users were using the two services to send red packets. Results of that war remains till today -- you can’t use Alipay in WeChat and can’t pay with WeChat Pay on Taobao. A surprising number of countries now accept WeChat Pay or Alipay For more insights into China tech, sign up for our tech newsletters , subscribe to our Inside China Tech podcast , and download the comprehensive 2019 China Internet Report . Also roam China Tech City , an award-winning interactive digital map at our sister site Abacus .