Add this to the growing list of ways drones are improving the world. The Brazilian government plans to use DJI drones to strengthen its fight against slave labor, which is troublesome in rural areas.

The Labour Ministry says six DJI Inspire 1 drones, which can shoot 4K video and capture 12 megapixel photos, will monitor suspicious activities starting next month in the state of Rio de Janeiro.

Other Brazilian states will start using similar equipment, according to the Labour Ministry.

Brazil defines slave labor as work carried out in degrading conditions or in conditions that pose a risk to the worker’s life. Forced labour, and working to pay off debts incurred with the employer, are also considered slave labour.

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“Drones don’t substitute the inspector’s physical presence, but they will be useful out in the country, in the case of farms that are hard to reach by road, for example,” says Bruno Barcia Lopes, coordinator of Rural Supervision at Rio de Janeiro’s Labour Secretariat.

In 2003, Brazil published a blacklist that named hundreds of companies that use slave labor. The blacklist is updated every six months, but if after two years a company has improved its working conditions and paid all its fines, it’s removed from the list.

So why did Brazil turn to drones? Reuters explains:

In December 2014, Supreme Court Justice Ricardo Lewandowski ordered the Labour Ministry to suspend the release of the blacklist. His decision was a response to an injunction filed by Brazil’s Real Estate Developers’ Association (Abrainc), whose members include the country’s largest construction companies.

Last year, OAS SA, which built two stadiums for Brazil’s World Cup, was put on the blacklist. Odebrecht, Latin America’s largest construction company, was accused last year of keeping 500 Brazilian workers in slave-like conditions at the construction site of a sugar and ethanol plant in Angola.

The government has been working to relaunch the list, using Brazil’s Freedom of Information Law as its main argument.

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Leonardo Sakamoto, head of Sao Paulo-based Reporter Brasil, an NGO that exposes slave labour cases, tells Reuters that “we can’t say things are better, or that slave labour has migrated to the cities, and it’s almost impossible to calculate numbers. Slave labour is like Silly Putty. Every time you squeeze it, it assumes a different form.”