Sending letters and stuff is fine, and might help combat censorship. But I think the only language they will truly understand is $$

Reduce usage of Visa/Mastercard/Paypal services wherever possible.

I'm going to buy a PSN gift card with cash for a game I want to buy and pay for my gas today with cash.

My next steam purchase? I'll be hitting my local store's gift card section with cash in hand.

Extra steps and inconvenience for me but another of the 1000 cuts into Visa for thinking siding with idiot Karens is the right thing to do.