[https://edition.cnn.com/2020/08/15/tech/tiktok-wechat-security-us-china-intl-hnk/index.html](https://edition.cnn.com/2020/08/15/tech/tiktok-wechat-security-us-china-intl-hnk/index.html) For years, the Great Firewall of China has blocked some of the largest online services coming out of the United States, including Google(GOOGL), Facebook (FB) and Twitter(TWTR).