In her speech, House suggested that it would be great if miners, as well as validators of proof-of-stake blockchains, came together and agreed not to mine OFAC-blacklisted transactions, as well as not to build upon blocks with such transactions. She also noted that having as much hashpower as possible in the U.S., where miners have to comply with the sanctions, would help make that vision a reality.
https://www.theblock.co/post/267759/bitcoin-faces-risk-of-protocol-level-censorship-as-miners-under-increasing-regulatory-pressure
so now they not only don't want people mining transactions on the OFAC list but if they happen to make it into a block they don't want miners to build on those blocks. just wow!
OFAC is in the USA. The Office of Foreign Assets Control. They want to control everything especially about bitcoin.
https://ofac.treasury.gov/
Thats not how it works. You can operate the machines to different locations. Also, Group B can still mine txns if Group A decided to not mine. Group B will get the rewards.
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