As expected, the U.S. Department of Justice today accused Google of abusing its monopoly power in online search. It was joined in this effort by 11 U.S. states, though several others are plotting their own separate cases.

“This morning the Department of Justice, along with eleven states, filed a civil lawsuit against Google for unlawfully maintaining a monopoly in general search services and search advertising in violation of the U.S. antitrust laws,” a statement attributed to the U.S. Attorney General reads. “This is a monumental case for the Department of Justice and, more importantly, for the American consumer.”

According to the statement, the accusation follows a 15-month investigation, during which the DOJ determined that Google no longer competes only on the merits but instead uses its monopoly power—and what it calls billions in monopoly profits—to “lock up key pathways to search on mobile phones, browsers, and next-generation devices, depriving rivals of distribution and scale.  The end result is that no one can feasibly challenge Google’s dominance in search and search advertising.”

The conclusion? This abuse harms users, advertisers, and small businesses in the form of fewer choices, reduced quality (including on metrics like privacy), higher advertising prices, and less innovation, the DOJ notes.

Interestingly, the DOJ also cites the success of its previous case against Microsoft, after which it says that there was a “wave of innovation” that increased competition. But today, 20 years later, Google, a key benefactor of that previous case, is now the abuser, and it is resorting to the same anticompetitive tactics that had previously driven Microsoft to dominance.

“If we let Google continue its anti-competitive ways, we will lose the next wave of innovators and Americans may never get to benefit from the ‘next Google’,” the DOJ says. “The time has come to restore competition to this vital industry.”

“Today’s lawsuit by the Department of Justice is deeply flawed,” a Google statement notes. “People use Google because they choose to, not because they’re forced to or because they can’t find alternatives.”

You can read the full complaint here. You can also read Google’s rebuttal here.