Recently, a user named @darengb stated on the social media platform that his SIM card was stolen by hackers, resulting in 22 ETH being stolen from his account. All the user's keys on friend.tech and the user's keys held on other people's accounts have been sold, and the remaining ETH in the user's wallet has been exhausted. This incident triggered heated discussions in the community. Some netizens believe that phone numbers are the weakest link in network security, and all wallet providers that use phone numbers to register may have the same vulnerability. On the other hand, as the telecommunications link industry behind friend.tech, Verizon's SMS verification method has also been questioned for security vulnerabilities. It is worth noting that Ethereum Lianchuang Vitalik has experienced similar SIM card swap attacks before.