Vitalik Buterin, co-founder of Ethereum, responded on the social platform "All major L2 networks in the mainnet can technically steal user funds at present", saying an important detail: the rules of Phase 1 require that the code can only be overturned if the security committee reaches the 75% voting threshold, and the members of the blocking quorum (i.e. ≥ 26%) need to be from outside the company. Optimism and Arbitrum both meet this requirement. Therefore, these organizations cannot steal funds unilaterally.