Now that might have sent a significant message with respect to ending this kind of bullshit, and to deliberately -- I'd argue, maliciously -- pushing the limits of what they can get away with.
I don't know how many users actually knuckled under to these fees. But even it it didn't represent an enormous amount of revenue, refunding it would have been a nice exercise for their management and administration to undergo. (I don't care how much of a "hassle" it might cause them.)
Your suggestion doesn't go far enough. If I were Verizon playing with these rules, I'd still try to collect fees. If were caught, I'd refund those fees and go about my business. No harm, no foul.
My point is that it's not really a penalty to just refund the money you took illegally. There must be punitive damages to make the risk of breaking the law more than just a profit or break even proposition. It should be a profit or lose more money than the risk is worth proposition for companies.
(That is, if your contract includes an arbitration clause)
"The FCC concedes that Verizon may charge $20 per month for customers who retain grandfathered unlimited data plans." http://arstechnica.com/gadgets/2012/07/tethering-apps-must-b...
So I won't be benefitting from this. The most ridiculous, bullshit part of all of this is that unlimited plans aren't unlimited anyway. They have "Fair Access Policy" data caps (5GB for Verizon IIRC) that are just like the modern plans with a tad higher caps. They just advertise differently. It's the same damn thing. And I don't get free tethering. Ridiculous.