On September 14, according to @OrangeFren, Monero was attacked again. A few hours ago, XMR underwent a reorganization of 18 blocks. To accept XMR payments, be sure to wait more than the usual 10 confirmations. Cosine Slow Fog said that if no one in the Monero community takes block reorganization seriously, the network will be hung under the "Sword of Damocles" for a long time. Even if the computing power does not exceed 51%, there may still be double spending risk.