Verizon tossed the ball back into the FCC's court last week when the service provider defended its policy of throttling data speeds for some customers.
In a July 25 blog post, Verizon detailed the process of slowing speeds for some of its heaviest unlimited-data-plan users—a move to which FCC Chairman Tom Wheeler did not take kindly.
The commission head responded with a letter to Verizon CEO Daniel Mead, with Wheeler saying that he was "deeply troubled" by the company's intent to slow speeds starting in October.
Days later, Verizon posted a notice acknowledging the FCC letter, and promising an official response to Wheeler's concerns.
"What we announced last week was a highly targeted and very limited network optimization effort, only targeting cell sites experiencing high demand," Verizon wrote on July 31. "The purpose is to ensure there is capacity for everyone in those limited circumstances, and that high users don't limit capacity for others."
Verizon followed up with an Aug. 1 letter from Kathleen Grillo, senior vice president of Verizon's federal regulatory affairs. According to her letter, which The Wall Street Journal procured, some customers use a "disproportionate amount of network resources and have an out-sized effect on the network."
"Not surprisingly, many of these heaviest users of the network are on unlimited data plans," she added.
A Verizon spokesman confirmed to PCMag that the company did respond to the FCC, but declined to share a copy of Grillo's letter, which has not yet been made public.
An FCC spokeswoman said the commission had received the letter and is reviewing it carefully.
"Rather than an effort to 'enhance [our] revenue streams,' our practice is a measured and fair step to ensure that this small group of customers do not disadvantage all others in the sharing of network resources," Grillo wrote in the Aug. 1 letter, according to the Journal.
In the letter, the executive claimed that other carriers have similar policies, but haven't drawn the same ire from the FCC.
Verizon and the FCC squared off in court in 2013 over whether the commission has the right to step in and regulate Internet-related matters.
The legal fight continued early this year as Verizon denied taking advantage of its net neutrality victory to throttle traffic and punish bandwidth-heavy services like Netflix. The streaming entertainment service later admitted to pushing out user alerts blaming their ISP—namely Verizon—for slow service.