I know a big guy, and he told me that he almost lost $ETH that time. At that time, there was a very popular project called DAO, which claimed to be a decentralized autonomous organization. Many people invested in it and even raised $150 million. This was an astronomical figure at the time, and everyone thought that DAO would be a big project that would change the world.
As a result, who would have thought that there was a big loophole in the code. A hacker discovered this loophole and easily stole more than $50 million in Ethereum! At that time, the community exploded all of a sudden, and everyone couldn't believe their eyes. This is not just about money, the key is that this shook everyone's trust in the blockchain. After all, isn't the blockchain about being tamper-proof? "Code is law" has always been a concept that everyone believes in, but now there is such a big loophole.
I remember that at that time, the community was divided into two factions. One faction advocated sticking to principles and not changing the blockchain no matter what happened. There was nothing they could do if the hacker succeeded, and this was a risk inherent in the system. The other group felt that they couldn't just sit back and do nothing, after all, so many people's money had been stolen, and action had to be taken.
In the end, the Ethereum community decided to take the hard fork approach, which simply means rolling back the blockchain to the state before the hacker attack so that everyone's funds can be restored. However, this also led to a big split. Some people who insisted on the concept of decentralization were unwilling to follow the fork. They chose to continue to maintain the original chain, which gave birth to the Ethereum Classic (ETC) we know today, while most people chose to go to the new chain after the hard fork, which is today's Ethereum (ETH).
After the incident, Ethereum was able to move forward, but the lesson of the DAO incident was very profound: although the blockchain claims to be decentralized and cannot be tampered with, when technology and ethics conflict, the community must make a difficult choice. We all realized at the time that the security of smart contracts was much more fragile than we thought, and later projects also put more effort into security audits.
