Verizon Wireless has just agreed to make the largest payment in FCC history, after the company admitted that it had billed users for millions of dollars in unintentional data use. The company will pay a whopping $25 million straight to the US Treasury and will refund at least $52 million to 15 million Verizon customers. It has also agreed to end these sorts of "mystery fees."

The fees were so mysterious because many customers had no idea how they were incurred, but each was so small that relatively few people complained. According to an FCC investigation, the fees could be incurred four different ways:

Unauthorized data transfers initiated automatically by applications (like games) built into certain phones;

Accessing certain Web links that were designated as free-of-charge (e.g., the Verizon Wireless Mobile Web homepage);

Unsuccessful attempts to access data when there was insufficient network coverage to complete the requested data transfer; and

Unwanted data transfers initiated by third parties and affecting customers who had content filters installed on their phones.

The fees have been paid by those without unlimited data plans since 2007. These "pay as you go" rates for data were $1.99 per megabyte or fraction thereof.

"Mystery solved: today's settlement with Verizon Wireless is about making things right and putting consumers back in the driver’s seat," said FCC enforcement chief Michele Ellison today. "Today’s settlement requires Verizon Wireless to make meaningful business reforms, prevent future overcharges, and provide consumers clear, easy-to-understand information about their choices. I am gratified by the cooperation of the Verizon Wireless team in the face of these issues, and pleased they are taking the high road."

That high road includes a set of commitments, including an end to these fees, reimbursement of customers, and a "data block" that customers can elect to have placed on their phones. In addition, Verizon will staff a Data Charge Task Force which will "monitor and resolve data charge complaints and other data charge-related issues going forward" and must report to the FCC.

FCC Chairman Julius Genachowski said the agreement sends a message to the public: "The FCC has got your back."