But that would mean someone who needed to call 911 couldn't - maybe their prepaid service ran out yesterday? It would be entirely ethical to allow anyone with working hardware who needed to call during an emergency to do so, and unethical to prevent people from calling because they didn't have a working SIM.

I think the intention is that any gray-market VoIP termination running over one of these is already blocking such calls. People usually don’t need to call 9-1-1 internationally, and there is some auto-enabled tracking in some countries for 911 calls that could leak the sim farm’s location.

TFA suggests they were used for swatting which I think would require 911 access to work.

I thought PSAP access numbers were the method of choice. They’re public.