According to CoinMeta, after suffering a $75 million hacker attack, Cronos decided to roll back the chain's history and delete over 10,000 blocks in order to reverse the vulnerabilities in the Tectonic protocol, successfully preserving approximately $69 million in frozen assets. This move sparked intense discussions about whether blockchains should possess the capability to be rolled back. On August 30th, validators of Cronos coordinated an emergency pause to restore the state from before the attack. The funds involved in this attack no longer exist after the rollback, and this incident has raised questions about the irreversibility of blockchain technology.