The U.S. Federal Communications Commission announced on Monday that it is imposing fines totaling around $200 million on the four major wireless carriers in the U.S. for unlawfully sharing and selling customers' location data without their permission.

The FCC announced that AT&T has been fined over $57 million, Verizon over $47 million, T-Mobile over $80 million, and Sprint over $12 million.

The FCC found that four companies were selling their customers' location data to third-party aggregators, who then sold the data to other companies. This created a gray market for cell phone users' historical and real-time location information. Many customers were unaware of this market for their data and did not give consent for their data to be sold.

According to the FCC, cell phone companies must protect customer information and get permission before using, sharing, or giving access to it.

The penalties were issued several years after news outlets exposed that the four mobile carriers were sharing this particular data with law enforcement agencies, bounty hunters, and various other groups.

Each of the four carriers disagreed with the ruling and expressed their plans to challenge it through the appeals process.