Updated January 24, 2023 at 1:59 PM ET
The Justice Department and eight states on Tuesday filed a lawsuit against Google over its digital advertising business, claiming the tech giant illegally monopolizes the market for online ads.
It is the second antitrust suit federal authorities have brought against the company's advertising empire, which has for years been under scrutiny over allegations of self-dealing and choking off competitors.
In its 155-page suit filed in the Eastern District of Virginia, authorities say acquisitions Google made to boost its advertising division effectively forced advertisers and publishers to use its products to the detriment of rival advertising firms.
"One industry behemoth, Google, has corrupted legitimate competition in the ad tech industry by engaging in a systematic campaign to seize control of the wide swath of high-tech tools used by publishers, advertisers, and brokers, to facilitate digital advertising," prosecutors wrote in the suit on Tuesday.
While the litigation is expected to drag on for some time, prosecutors are asking a federal judge to force Google to break up its advertising segment from the rest of the company.
Authorities allege that the world of online advertising has been slanted to favor Google "for reasons that were neither accidental nor inevitable."
For instance, in 2017, Google purchased DoubleClick, which makes widely used advertising tools, for $3.1 billion.
It gave Google direct access to the inventory of website publishers and the ad-serving technology used by those publishers.
Google also controls a major online advertising exchange where companies bid in real time to reach an intended audience on the Internet.
The DoubleClick purchase gave the company power on both sides of online advertising commerce: Selling ads to publishers and influence over the tools publishers use to display ads, not to mention the online auction house where the transactions take place.
Prosecutors allege Google abused that power by essentially rigging the system in Google's favor.
The acquisition gave Google "the unilateral power to implement a series of anticompetitive restraints," meaning it allowed Google to build up barriers. Google used "its dominance on both the publisher and advertisers of the market to inhibit competition across the entire tech stack," authorities wrote in the suit.
The suit has allegations similar to those in a lawsuit brought by a coalition of states in 2020 targeting Google's advertising business. A federal judge in September allowed the case to move forward, while narrowing the scope of the allegations.
Google did not immediately return a request for comment.
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