Artificial intelligence is being used for a dizzying array of tasks, but one of the most successful is also one of the scariest: automated surveillance. Case in point is Chinese startup SenseTime, which makes AI-powered surveillance software for the country’s police, and which this week received a new round of funding worth $600 million. This funding, led by retailing giant Alibaba, reportedly gives SenseTime a total valuation of more than $4.5 billion, making it the most valuable AI startup in the world, according to analyst firm CB Insights.

This news is significant for a number of reasons. First, it shows how China continues to pour money into artificial intelligence, both through government funding and private investment. Many are watching the competition between China and America to develop cutting-edge AI with great interest, and see investment as an important measure of progress. China has overtaken the US in this regard, although experts are quick to caution that it’s only one metric of success.

Secondly, the investment shows that image analysis is one of the most lucrative commercial applications for AI. SenseTime became profitable in 2017 and claims it has more than 400 clients and partners. It sells its AI-powered services to improve the camera apps of smartphone-makers like OPPO and Vivo; to offer “beautification” effects and AR filters on Chinese social media platforms like Weibo; and to provide identity verification for domestic finance and retail apps like Huanbei and Rong360.

Most notably, SenseTime also outfits Chinese law enforcement with facial recognition and tracking services. For example, the company says that software it provides for the security bureau of Guangzhou (one of China’s three biggest cities with a metropolitan population of around 25 million) is used to match surveillance footage from crime scenes to photos from a criminal database, and has identified more than 2,000 suspects and solved “nearly 100 cases.”

Justin Niu, a partner at IDG, an early investor in SenseTime, told The Financial Times in January: “SenseTime and its competitors can grow so fast compared to elsewhere in the world because video surveillance is a big deal in China, the government controls the budget and there’s a huge budget for it so they can manage society.” According to Bloomberg, SenseTime is currently developing software code-named Viper that will “parse data from thousands of live camera feeds” and will be used by the police to “track everything from vice and accidents to suspects on blacklists.”

Privacy and free speech advocates say that China is already using similar technology to track and harass political opponents, and warn that AI-augmented surveillance could mean the death of privacy. SenseTime co-founder Xu Li told Bloomberg that the company’s technology “will not affect privacy because only authorized persons can access it.”

But China isn’t the only country interested in this use of AI, and companies around the world are working on similar systems. SenseTime is a leader in this field, but its latest funding round suggests this sort of real-time video analysis is only going to become more widespread.

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