Canada Canada Competition Bureau big tech

Canada's Google Adtech Case Now Hinges on Witnesses It Cannot Reach

Ottawa's bid to compel US-based ex-Googlers shows a national break-up case resting on conduct and evidence located abroad.

Canada's Google Adtech Case, By the Numbers People of Internet Research · Canada 90% Publisher ad-server share Bureau's alleged Google share of C… ~$91B Penalty Google warns of Google's characterization of the m… 2 Tools targeted for divestiture Bureau seeks the sale of DFP and A… Apr 2025 US monopoly ruling US judge found Google liable for t… peopleofinternet.com

Key Takeaways

On May 7, 2026, Canada's Competition Bureau asked the Competition Tribunal to compel evidence from former Google employees living in the United States, after none of the people it wanted to question agreed to testify voluntarily. It is a procedural footnote with a large lesson inside it: the Bureau's signature big-tech case — an application to break up Google's advertising-technology business — increasingly depends on facts, documents, and people that sit outside Canadian jurisdiction.

How the case got here

The Bureau filed its application with the Competition Tribunal in late November 2024, alleging that Google abused its dominant position in online advertising and asking the Tribunal to force Google to divest two tools at the centre of the ad-tech "stack": its publisher ad server, DoubleClick for Publishers (DFP), and its ad exchange, AdX. The Bureau's figures describe near-total control of the pipes: roughly 90% of publisher ad servers, 70% of advertiser networks, 60% of demand-side platforms, and 50% of ad exchanges in Canada (Competition Bureau backgrounder; Newsweek).

Google's first line of defence was constitutional. It argued the penalty the Bureau seeks — three times the benefit derived from the conduct, or, if that cannot be calculated, 3% of Google's worldwide gross revenue — was so large (Google warned of a figure approaching $91 billion) that it amounted to a "true penal consequence" triggering Charter protections. In early March 2026, Tribunal judge Andrew Little dismissed that challenge, calling the feared penalty "hypothetical at best" and noting that large fines may be necessary to deter non-compliance (Globe and Mail). With the constitutional off-ramp closed, the case turns to evidence — and that is where the witness problem surfaces.

The strongest case for the Bureau

It would be a mistake to treat this as a watchdog overreaching against an innocent firm. The conduct the Bureau describes is not speculative. In April 2025, US District Judge Leonie Brinkema found Google liable for unlawfully monopolizing both the open-web ad-exchange and publisher-ad-server markets, and for illegally tying the two together — citing a 91% share for its DoubleClick server and finding "substantial" harm to publishers and to the open web (Simpson Thacher analysis). Canadian publishers and advertisers transact in the same global stack, so the harm the Bureau alleges is real and locally felt. When a firm runs the auctioneer, the buy-side tool, and the sell-side server simultaneously, the conflict of interest is structural, not hypothetical. A national regulator declining to act simply because the defendant is foreign would be abdication, not restraint.

Where proportionality breaks down

Grant all of that, and the May 7 motion still exposes the core difficulty. The witnesses the Bureau cannot reach are former Google employees in the United States. The conduct was designed and executed largely in the US. And the most authoritative finding of illegality already exists — Brinkema's ruling, now in its remedy phase, where the US Justice Department is itself seeking divestiture of AdX and DFP. Canada is, in effect, litigating the same conduct, against the same products, toward the same break-up remedy, but with a fraction of the evidentiary reach.

That raises a proportionality question the Bureau should answer squarely. A structural break-up is the most drastic tool in competition law; layering on a penalty pegged to worldwide revenue compounds it. The Tribunal was right that the $91-billion figure is hypothetical — but a remedy calibrated to global turnover, for harm measured in a single mid-sized market, is hard to square with the principle that sanctions should track the injury. If AdX and DFP are divested globally as a result of the US case, the marginal benefit of a separate Canadian break-up order shrinks toward zero, while its costs — years of cross-border discovery, compelled foreign testimony, and legal uncertainty for every Canadian publisher mid-stream — do not.

A more proportionate path

The pro-competition goal here is sound; the instrument is heavier than the harm requires. Three adjustments would serve Canadian advertisers better than a parallel break-up race.

None of this means letting dominant conduct slide. It means matching the remedy to the injury and to the jurisdiction's actual reach. The witness motion is a useful signal: a break-up case built largely on extraterritorial conduct will keep colliding with the limits of national process. Better to win durable, proportionate relief for Canadian publishers than to chase the most dramatic remedy and discover, late in a long trial, that the decisive evidence never crossed the border.

Sources & Citations

  1. Competition Bureau — backgrounder on Google suit
  2. Competition Bureau — statement on dismissal of Google's constitutional challenge
  3. Globe and Mail — Tribunal rejects Google's constitutional challenge
  4. Global Competition Review — Google told to confirm foreign witness testimony
  5. Newsweek — Canada sues Google to break up advertising business
  6. Simpson Thacher — US court rules Google a monopolist in ad tech (Brinkema, Apr 2025)