He could be talking about the issue of "mining centralization": - https://www.reddit.com/r/btc/comments/7dl4r3/miner_centralization_question/ https://www.redd

He could be talking about the issue of "mining centralization": - https://www.reddit.com/r/btc/comments/7dl4r3/miner_centralization_question/ https://www.reddit.com/r/btc/comments/7dl4r3/miner_centraliz... - https://medium.com/@cloudycalvin/potential-threats-to-bitcoin-1-mining-centralization-1fc1090694e5 https://medium.com/@cloudycalvin/potential-threats-to-bitcoi...