Then the Chairman of the FCC accused Verizon of potentially pursuing a "loophole designed to enhance your revenue streams" in a scathing demand letter.
Now Verizon has responded with a letter of their own, claiming that their throttling plan is fair and balanced and not at all controversial.
Verizon's letter clarifies that the throttling of unlimited customers will only occur "under very limited circumstances .. at particular cell sites experiencing unusually high demand."
Only users who rank in the top 5% of data consumers will be subject to slowdowns.
"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 during times of high demand."
With the way Verizon's network has been growing - a lot of cell sites are very likely to be under "high demand" perpetually during prime hours. And at the moment all it takes is using 4.7GB a month to get on Verizon's naughty list - so this is still potentially going to have a huge impact on many users - some of whom regularly use dozens or even hundreds of gigs on grandfathered Verizon unlimited plans.
And the big unanswered question remains just how slow will users be throttled to? If Verizon makes the network painful enough, that will be a strong incentive for unlimited users to give up their old plans and switch to metered and unthrottled accounts.
With both the FCC and Verizon ratcheting up their war of words, this one may ultimately end up decided in the courts.
The Verge has a few more details and quotes from Verizon's letter - I have not seen the full original published anywhere yet.