英国がGoogleに命令：出版社がAI検索機能からオプトアウトできる仕組みを義務化 Google must let publishers opt out of AI Search features, rules UK

The UK's Competition and Markets Authority has introduced a new conduct rule requiring Google to give online publishers a genuine opt-out from its AI Search features, including AI Overviews. The ruling marks a significant regulatory intervention into how the world's dominant search engine can use third-party content to power its artificial intelligence products.

At the heart of the dispute is a structural problem that publishers have complained about for years: in practice, opting out of Google's indexing via robots.txt means opting out of search traffic entirely — a commercial non-starter for most content businesses. The CMA's new rule targets this all-or-nothing dynamic by requiring Google to offer a disaggregated opt-out, letting publishers decline AI feature participation without sacrificing their presence in traditional search results.

Google rolled out AI Overviews at scale in the United States in 2024, displaying AI-generated summaries at the top of search results pages. News publishers were among the loudest critics, reporting declines in click-through rates as users found answers without visiting source sites. The tension between platform efficiency and publisher sustainability has since spread into regulatory debates across Europe, Australia, and now decisively in the UK.

The CMA has been operating with expanded powers under the UK's Digital Markets, Competition and Consumers Act, which allows it to designate companies with Strategic Market Status and impose binding conduct requirements. Google is currently under SMS investigation, making it subject to exactly this kind of targeted behavioral rule. Non-compliance could expose the company to significant financial penalties.

The broader context matters here. Across the Atlantic, US publishers have pursued litigation against AI companies over training data use, with mixed results. The EU's AI Act and existing copyright frameworks create their own compliance pressures. The UK's approach — imposing a specific, operational opt-out mechanism rather than litigating abstract copyright questions — could serve as a model for other jurisdictions looking for practical remedies rather than drawn-out legal battles.

For Google, the challenge is balancing its ambition to make search more AI-native against the reality that its products depend on a healthy, incentivized publishing ecosystem. If publishers increasingly wall off their content or reduce output because AI features cannibalize traffic, the quality of training and retrieval data could suffer over time — a long-term risk that regulators and the company alike appear to be grappling with.

How Google implements the opt-out mechanism in practice will be closely watched. The technical and commercial details — whether opt-outs are granular by feature, easy to toggle, and honored promptly — will determine whether the rule achieves its intent or becomes another compliance checkbox. Publishers, regulators, and competing AI search entrants like Perplexity and Microsoft's Copilot-integrated Bing will all be paying attention.