According to a report jointly released by X-explore and WuBlockchain, there are major loopholes in Arbitrum's anti-Sybil attack detection rules, and more than 279,328 associated addresses have received airdrops, of which 148,595 are Sybil attack addresses. Associated addresses received approximately 557 million ARBs, accounting for 47.96% of the total airdropped tokens; Sybil attack addresses obtained approximately 253 million ARBs, accounting for 21.8% of the total airdropped tokens. The article stated that the rules formulated by Arbitrum cannot effectively prevent the following four types of Sybil attacks: Sybil attacks associated with less than 20 addresses; Sybil attacks through exchanges, cross-chain bridges, and smart contracts; Sybil attacks that obviously collect NFT or funds; Sybil attacks that have obvious batch operations on Optimism, Ethereum and other chains. In addition, this Arbitrum address not only includes EOA accounts, a total of 1007 contract addresses received about 1 million ARB airdrops.