Sources: DOJ investigators are asking ad executives whether Google's plan to ban third-party cookies will hobble its smaller rivals
Context & Ripple Effects
The DOJ's cookie questions extend an inquiry that has been building for over a year: back in February 2020 the agency reached out to more than a dozen publishers, agencies, and ad tech rivals as Google's ad tools came under focus (that earlier sweep), and by September 2020 sources said Google's pro-privacy plan to block trackers had itself boosted the US antitrust probe because publishers saw it tilting the field. The move also internationalized quickly — the UK's competition watchdog opened its own investigation into the Chrome cookie removal proposals in January.
What changed this week is who is being asked: rather than just document collectors, DOJ investigators are now putting the competitive question — whether banning third-party cookies will hobble Google's smaller ad rivals — directly to ad executives. That frames Chrome's control of browser-level tracking as an access point competitors depend on, not merely a privacy feature.
First-order effects
- Ad executives interviewed by the DOJ effectively become sworn evidence on whether the cookie ban advantages Google's own ad business, giving the agency named testimony about harm to smaller rivals.
- Google now faces parallel scrutiny on the same proposal from both the DOJ and the UK's competition watchdog, meaning one product decision must satisfy two regulators with different processes.
Second-order effects
- Publishers and ad tech firms gain a formal channel to argue their dependence case, converting complaints about an 'unfair playing field' into potential inputs to enforcement action against Chrome's design choices.
- Rival browsers and ad platforms can position their own approaches to post-cookie targeting as the less anticompetitive alternative, making interoperability and data-access terms a selling point against Chrome.
Third-order effects
- If the pattern holds through Google's eventual rollout, browser-level identity changes get treated as competition events requiring regulator sign-off rather than unilateral product updates — a dynamic visible later when Google restricted cookies for just 1% of Chrome users (the first 1% test) and marketers, adtech firms, and publishers still said the market was unprepared.
- The structural endpoint is that whoever controls the access layer — the browser through which user identity flows — holds pricing power over the entire ad supply chain, which is precisely why regulators keep circling it.
The trend: Regulators are reframing platform owners' privacy-driven removal of third-party identifiers as antitrust conduct, forcing Chrome's identity roadmap to be sequenced around competition review.