Unfortunately, the only way to fight this is with a customer boycott. That is to say that Verizon (and others) will not cease such clandestine activites without their advertisers pulling out.
The only way advertisers will pull out is with customer backlash, and that means we have to stop buying from companies who use such advertising.
And can you imagine what would have been lost had the public reacted in knee jerk fashion by keeping those letters private because of some short sighted political pundits?
So tell me again why we're okay with this today?
The US constitution stands on it's own merits. The daily tos and fros of negotiating the thing over those 4 months are irrelevant.
And yet, for decades after that original publishing of the US Constitution, those very tos and fros of negotiating were slowly trickled out, leading to some of the most foundational Supreme Court rulings which have preserved our country's freedoms.
Dismissing the process for the results is like missing the trees for the forest. Just as in politics, in the scientific method, the ends do not always justify the means, and pretending otherwise can lead to atrocities like eugenics. Apologies for invoking Godwin's law, but it does sufficiently demonstrate the point.