In last year's trial, Google argued that its product was superior and dominated online search.
And the company appears to be using a similar defense strategy in its ad tech case.
When asked for a statement, the BBC referred to a 2023 blog post that said: “No one is forced to use our ad technology – they choose to use it because it’s effective.”
The Meta judge held a status conference on Friday as he began proceedings to decide what remedies to take against Google's actions.
“The DoJ has clearly had a huge win and they will continue to build on that,” Dan Ives, managing director at Wedbush Securities, told the BBC.
He said he expected such a solution would involve “adjusting the business model” rather than breaking up the company.
Meanwhile, in Judge Brinkema's courtroom, the Justice Department's attempts to prove its case could face a difficult hurdle because of the arcane procedures regulating advertising technology.
“We all use search. We all intuitively understand the product,” said Rebecca Ho Allensworth, an antitrust professor at Vanderbilt University School of Law.
By comparison, advertising technology is “so complex that it seems really difficult for the government to make a clear and simple monopoly claim here.”
The U.S. isn't the only country where regulators are unhappy with Google's ad tech business.
Britain's Competition and Markets Authority said on Friday that it believed Google was abusing its dominance in the ad tech industry, following initial findings from its investigation.
The report found that Google used anti-competitive practices to dominate the online advertising technology market, and that the potentially illegal actions could harm thousands of UK publishers and advertisers.
A Google spokesperson said the decision was based on a “misunderstanding” of the ad tech sector.
