Network operators and equipment makers have been telling us to brace for the incredible potential of 5G for the past half-decade. But despite throwing out ideas for how to use that incredible speed and bandwidth, no one really has a clear idea on what kind of killer app will emerge.

Well, at least one country knows how to rein in the power: China. It has been developing a surveillance economy and has been using cameras and artificial intelligence to enforce society values. The latest example of this is on the Shenzhen Metro.

The South China Morning Post reports that the Shenzhen Metro Company has partnered with telecom giant Huawei in testing technologies with the 5G grid, including robot patrols inside stations, equipment inspections with drones and even automatic fare deduction through facial recognition.

The agency says that passengers will need to upload a photo and link a payment source to their online metro accounts to use the new feature once it eventually debuts. The system was demonstrated at Futian station, but will eventually expand to the rest of the network — one that, on average, makes 4.8 million journeys possible every day.

Currently, Shenzhen Traffic Police are also enforcing pedestrian laws via facial recognition surveillance. The department shames jaywalkers by posting obscured pictures of them with their surname and obscured ID numbers to an online portal.

Dozens of other local governments have already been giving merits and demerits to citizens through surveillance. This has affected people’s credit ratings and has put people on government “blacklists,” limiting licenses to drive and even access to train and plane tickets, while giving good-doers discounts on bank loans, food and travel. A nationalized social credit system could come to effect as early as 2020.

While a lot of this information will be harvested through existing records and even citizen reporting, 5G’s massive potential could bring anyone’s behavior in the public eye into immediate consideration and judgment through artificial intelligence.