One of the biggest characteristics of blockchain is that it cannot be tampered with, and all content will be retained. However, this itself may be a false proposition. Decentralized servers are still centralized, and in fact, there are too few that can run all nodes. The consensus mechanism is also uneven, and even AWS may suddenly shut down, causing some public chains to be inaccessible. Decentralization and immutability are currently just illusions of consensus under ideal conditions. Once the majority of nodes or validators are controlled, the data on the chain can be legally tampered with or rolled back. Imagination is beautiful, expectations are also beautiful, but reality is still cruel. At least for now, it's like this.