Google's recent release of its Gemma 3 family of open AI models has garnered praise for their impressive efficiency, but developers are raising concerns over the restrictive licensing terms that come with them. The controversy highlights a broader issue in the AI industry, where companies like Meta and Google apply custom, non-standard licensing terms to their openly available models, creating legal challenges for businesses that want to use them.

Nick Vidal, head of community at the Open Source Initiative, notes that the restrictive and inconsistent licensing of so-called "open" AI models is creating significant uncertainty, particularly for commercial adoption. "While these models are marketed as open, the actual terms impose various legal and practical hurdles that deter businesses from integrating them into their products or services," Vidal said.

AI startup Cohere, for example, has been clear about its intent to support scientific – but not commercial – work on top of its models. However, Gemma and Meta's Llama licenses have restrictions that limit the ways companies can use the models without fear of legal reprisal. Meta's license prohibits developers from using the "output or results" of Llama 3 models to improve any model besides Llama 3 or "derivative works." It also prevents companies with over 700 million monthly active users from deploying Llama models without first obtaining a special, additional license.

Gemma's license is generally less burdensome, but it does grant Google the right to "restrict (remotely or otherwise) usage" of Gemma that Google believes is in violation of the company's prohibited use policy or "applicable laws and regulations." These terms don't just apply to the original Llama and Gemma models, but also to models based on Llama or Gemma, including those trained on synthetic data generated by Gemma.

Florian Brand, a research assistant at the German Research Center for Artificial Intelligence, believes that licenses like Gemma and Llama's "cannot reasonably be called 'open source.'" "Most companies have a set of approved licenses, such as Apache 2.0, so any custom license is a lot of trouble and money," Brand said. "Small companies without legal teams or money for lawyers will stick to models with standard licenses."

Brand noted that AI model developers with custom licenses, like Google, haven't aggressively enforced their terms yet. However, the threat is often enough to deter adoption, he added. "These restrictions have an impact on the AI ecosystem — even on AI researchers like me," Brand said.

Han-Chung Lee, director of machine learning at Moody's, agrees that custom licenses such as those attached to Gemma and Llama make the models "not usable" in many commercial scenarios. Eric Tramel, a staff applied scientist at AI startup Gretel, also expressed concerns about the licenses, citing the potential for "clawbacks" and the uncertainty surrounding model derivatives and distillation.

The scenario that deployers most fear, Tramel said, is that the models are a trojan horse of sorts. "A model foundry can put out [open] models, wait to see what business cases develop using those models, and then strong-arm their way into successful verticals by either extortion or lawfare," he said.

Yacine Jernite, head of machine learning and society at AI startup Hugging Face, called on providers like Google to move to open license frameworks and "collaborate more directly" with users on broadly accepted terms. "Given the lack of consensus on these terms and the fact that many of the underlying assumptions haven't yet been tested in courts, it all serves primarily as a declaration of intent from those actors," Jernite said.

Vidal emphasized the urgent need for AI models that companies can freely integrate, modify, and share without fearing sudden license changes or legal ambiguity. "The current landscape of AI model licensing is riddled with confusion, restrictive terms, and misleading claims of openness," Vidal said. "Instead of redefining 'open' to suit corporate interests, the AI industry should align with established open source principles to create a truly open ecosystem."

As the AI industry continues to grow and evolve, the debate over licensing terms is likely to intensify. With companies like Google and Meta pushing the boundaries of AI innovation, it's crucial that they prioritize transparency, collaboration, and open standards to ensure that their creations can be used for the greater good.