Closing arguments raise stakes for breakup talk

A landmark antitrust showdown over Google’s advertising empire is entering its final phase after closing arguments in a U.S. federal court. Judge Leonie Brinkema, who has already ruled that Google holds illegal monopolies in key parts of the online ad market, repeatedly pressed government lawyers on how quickly any remedy could take effect. The Justice Department wants structural changes, including forcing Google to spin off its AdX exchange and possibly its publisher ad-server business. Officials argue that only breaking up the vertically integrated stack will truly restore competition for the billions of ad impressions traded every day across the open web.

Google paints a starkly different picture. Company lawyers insist that its tools help publishers and advertisers reach audiences more efficiently, and that users benefit from more relevant ads and free services. They contend that behavioural remedies – such as limits on how Google can bundle products, share data or prioritise its own services – would address the court’s concerns without the disruption of a forced divestiture. In court, counsel warned that carving out AdX would be technically complex, require years of engineering work and risk outages for publishers who depend on the platform’s auction systems. Any breakup ordered today, they say, could be outdated by the time appeals are exhausted in a fast-moving digital ad market.

Big Tech watches for the next Microsoft moment

Judge Brinkema’s questions highlighted that tension between speed and impact. She noted that Google is almost certain to challenge her liability ruling, meaning a structural remedy might be put on hold during a lengthy appeal. That raises the prospect of an ad market that remains concentrated for years while lawyers fight over details. Government attorneys countered that letting an unlawful monopoly stand would punish smaller ad-tech rivals and news publishers that have already lost revenue to Google’s dominance. They stressed evidence that Google used its control over tools on both the buy and sell sides of the market to tilt auctions in its favour, steering higher-value deals towards its own platforms.

Beyond the courtroom drama, the stakes extend far beyond Silicon Valley. A government victory that leads to a breakup would mark the most aggressive antitrust action against a U.S. technology giant since the Microsoft case in the late 1990s. Regulators in Europe and elsewhere, already pursuing their own investigations into digital markets, are watching closely. If Google is forced to separate parts of its ad business, it could embolden authorities to pursue similar remedies against other platforms that dominate online commerce and social media. Conversely, if the court opts for modest conduct restrictions, big tech firms may conclude that structural breakups are unlikely even when regulators prove monopoly abuse.

For advertisers and publishers, the uncertainty is already shaping strategy. Some brands have been experimenting with rival ad exchanges and direct deals with media outlets to reduce their reliance on Google’s stack. News organisations in particular argue that more competitive auctions could lift the prices they receive for inventory, helping to shore up struggling business models. Yet many also worry about short-term turbulence if a court-ordered restructuring disrupts the systems they use to place and measure ads. With the judge signalling that “time is of the essence” but offering no hint of her final decision, the industry is bracing for a ruling next year that could redefine who captures value from digital advertising – and how much power one company can wield over the plumbing of the modern web.