Tootfinder

The unique selling point of the #blockchain in public lore is, that you can not change anything once it is written to the blockchain. But of course you can.
https://www.

Ravencoin, a blockchain built from Bitcoin’s code, could roll back four days of transactions
Two mining pools controlling most of Ravencoin’s hashpower are building a replacement chain from before Friday’s first invalid block, putting deposits, withdrawals and payments made since then at risk of reversal.