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China's retaliatory import tariffs against the U.S. are unlikely to hit technology giants, including Alphabet and Facebook, because such services have already been blocked by Beijing.

On Thursday, President Donald Trump signed an executive memorandum to impose tariffs on up to $60 billion in Chinese imports. China then hit back with tariffs of its own on 128 U.S. products with an import value of $3 billion. China's government hasn't specifically named the technology sector as one of its targets, but could potentially do so if the trade war was to escalate. Even if it did, analysts have said that the big technology giants in the U.S. would be insulated. Facebook and Google, for example, are blocked in China by the government's internet censorship system, known as the Great Firewall.

In 2016, Netflix launched its biggest international push, but stayed out of China. The streaming service currently serves a small portion of its original content in China via Baidu's iQiyi video platform. Chinese internet giant Baidu, which is often dubbed the "Google of China," is the dominant search player in China. Netflix, meanwhile, faces competition not only from Baidu, but also from Tencent and Alibaba, which have their own video content products. Amazon has a small presence in China with its retail business and, in 2016, launched its Prime subscription service in the world's second-largest economy. Amazon is estimated to have a negligible share of the online shopping market in China, which is dominated by domestic players Alibaba and JD.com. Even the e-commerce giant's cloud business in China is small in comparison to local players. The story is similar for all the technology companies. Government censorship and rules have hampered the tech sector's ability to grow in China. And that means they have small businesses in the country, and would mean any tariffs imposed on them by Beijing would have a small effect.