Google is once again in the crosshairs for alleged monopolistic behavior, accused of dominating multiple digital ad products.

The US government has been trying to crack down on Big Tech and Google has been a prime target. The Department of Justice has once again taken aim at the company, this time over its ad business. The DOJ was joined by Attorneys General of California, Colorado, Connecticut, New Jersey, New York, Rhode Island, Tennessee, and Virginia.

The lawsuit alleges that Google abuses its control of the various components of the online advertising technology, called the “ad tech stack.” Because Google controls the entire stack, the company is in a position to unfairly dictate terms. The lawsuit claims Google has leveraged that position to force competitors out of the market or buy them out, as well as force companies to increasingly use its products exclusively.

“Today’s complaint alleges that Google has used anticompetitive, exclusionary, and unlawful conduct to eliminate or severely diminish any threat to its dominance over digital advertising technologies,” said Attorney General Merrick B. Garland. “No matter the industry and no matter the company, the Justice Department will vigorously enforce our antitrust laws to protect consumers, safeguard competition, and ensure economic fairness and opportunity for all.”

In particular, the DOJ’s claims focus on four areas:

• Eliminating competition through acquisitions.
• Forcing customers to use Google’s ad products.
• Interfering with ad auction competition.
• Manipulating ad auctions to protect its own business at the expense of competitors.

“The complaint filed today alleges a pervasive and systemic pattern of misconduct through which Google sought to consolidate market power and stave off free-market competition,” said Deputy Attorney General Lisa O. Monaco. “In pursuit of outsized profits, Google has caused great harm to online publishers and advertisers and American consumers. This lawsuit marks an important milestone in the Department’s efforts to hold big technology companies accountable for violations of the antitrust laws.”