China customs officials have taken down smugglers who used drones to carry iPhones from Hong Kong into Shenzhen. They managed to transport 500 million yuan (about ₦28,728,000,000) worth of refurbished iPhones before the operation was busted, according to Reuters.

Under the cover of dark, the group of 26 used the unspecified drones to “fly two 200-meter (660-feet) cables between Hong Kong and the mainland.” From there, they loaded around 10 iPhones into small bags and sent each across the cable system. The smugglers could move up to 15,000 iPhones each night, so they managed to get things running pretty efficiently.

The local, state-owned Legal Daily reported this to be “the first case found in China that drones were being used in cross-border smuggling crimes.” As a result, Shenzhen customs plans to keep a close eye on this high-tech smuggling — perhaps using its own drones to help combat illegal cross-border activity.

Last year, China implemented a policy requiring owners of civilian drones over a given weight to register their flying gadgets using their real names. As is the case in the US and elsewhere, China has experienced its share of drone incidents, leading to delayed or disrupted flights. In the United States, drone owners must register any device over 0.55 pounds.