As another form of fighting back, I suggest that anyone with MasterCard and/or Visa credit cards to stop using them for any and all transactions where possible. Same goes for PayPal. Suggest using Discover instead if you have it, as I've not seen it mentioned in any of these censorship stories. Discover is now accepted at most places, including itch.io and Steam. Spread the word: Boycott MC/Visa/PayPal.
I have already switched to using Discover wherever possible, even before this happened, because this isn't even the first time Visa and Mastercard have done this sort of thing, just the most high-profile. And previous times didn't even have someone else pestering them to do it; the companies just did it entirely on their own. Unfortunately, many places I go still don't accept Discover, no matter what Discover's advertising may claim. Online shopping is not the end-all, be-all of existence.
Discover is now accepted at many more places than it used to be, and pretty much everywhere online and offline that I do any shopping, but I hear ya. It's just, do what you can, ya know, that's all I'm saying. It's good to know you've already taken measures due to having noticed undesirable behavior in other situations.