MEXICO CITY (AP) — A cartel in the embattled central Mexico state of Michoacan set up its own makeshift internet antennas and told locals they had to pay to use its Wi-Fi service or they would be killed, state prosecutors said Wednesday.

Dubbed “narco-antennas” by local media, the cartel’s system involved internet antennas set up in various towns built with stolen equipment.

The group charged approximately 5,000 people elevated prices between between 400 and 500 pesos ($25 to $30) a month, the Michoacán state prosecutor’s office told The Associated Press. That meant the group could rake in around $150,000 a month.

People were terrorized “to contract the internet services at excessive costs, under the claim that they would be killed if they did not,” prosecutors said, though they didn’t report any such deaths.

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Local media identified the criminal group as the Los Viagras cartel. Prosecutors declined to say which cartel was involved because the case was still under investigation, but they confirmed Los Viagras dominates the towns forced to make the Wi-Fi payments.

Law enforcement seized the equipment late last week and shared photos of the makeshift antennas and piles of equipment and routers with the labels of the Mexican internet company Telmex, owned by powerful Mexican businessman Carlos Slim. They also detained one person.

Mexican cartels have long employed a shadow network of radio towers and makeshift internet to communicate within criminal organizations and dodge authorities.

But the use of such towers to extort communities is part of a larger trend in the country, said Falko Ernst, Mexico analyst for Crisis Group.

Ernst said the approximately 200 armed criminal groups active in Mexico no longer focus just on drug trafficking but are also “becoming de facto monopolists of certain services and other legal markets.” He said that as cartels have gained firmer control of large swaths of Mexico, they have effectively formed “fiefdoms.”

Ernst said gangs in some areas are charging taxes on basic foods and imported products, and noted they have also infiltrated Michoacan’s lucrative avocado business and lime markets as well as parts of local mining industries.

“It’s really become sort of like an all around game for them. And it’s not specific to any particular good or market anymore. It’s become about holding territory through violence,” he said. “It’s not solely about drugs anymore.”