Definitely not France. The STOP message is ignored. They also created a global “block” list that you can subscribe to. This list is handled by an advertising company…
French mobile networks are having a bit of a clampdown at the moment. My employer sends SMS to France and they've been absolutely on the warpath if they think you're not respecting STOP and CONTACT messages.
Wait. Really? I had no idea this is true. You're saying there's a US law that means replying STOP is intercepted by verizon/T-mobile/etc. and the sender never has to see it?