What do you do as a railway operator when millions of dollars worth of material has been stolen in a spree of 900 thefts over 10 months?

Employ drones to better secure your trains, of course.

Polish rail freight operator PKP Cargo announced in October 2014 its planned use of drones, and it appears the strategy has paid off. In the video below, a drone captured footage of thieves attempting to steal coal from a PKP Cargo freight train. According to the Polish Radio External Service, the images were clear enough to pass onto police, which in turn arrest the robbers.

In the first 10 months of 2014, PKP reported almost 900 cases of theft, adding that the situation will only get worse during the winter months as coal use heats up.

“Theft of raw materials during transport is a hurdle which we have faced for a number of years, and the losses incurred amount to millions [of zloty] each year,” Maciej Borecki, director of Security and Audit PKP Cargo, said during the announcement to use drones for security purposes. “In order to limit the scale of these crimes, this year we have decided to intensify preventive measures and make use of modern technology.”

Watch the robbers drive and run away once they realize the drone is filming them in the video below.