PANews reported on April 16 that Ethereum co-founder Vitalik Buterin, in response to developer raulk's discussion about open-source licenses on the X platform, stated that the Copyleft license can serve as a strong self-restraint mechanism to prevent future versions of a project from becoming closed-source—unless the project incurs the cost of a complete rewrite, and even then, it may face legal risks associated with derivative works.

Previously, raulk argued that in the era of AI agents and "vibe coding" (generating code through intuitive interaction with AI), the role of copyleft licenses in protecting open-source code from closed-source exploitation is diminishing. This is because attackers can bypass GPL obligations by reverse engineering LLM code and reimplementing it. He believes that only large, complex codebases like Linux and MySQL, which have withstood decades of real-world testing, still possess a strong moat; for smaller codebases, copyleft is no longer sufficient to prevent others from circumventing obligations through rewriting.