Attorney General Curtis Hill today joined nine other attorneys general in filing a lawsuit against Google for multiple violations of federal and state antitrust laws in connection with its multiple roles in the multibillion-dollar online display advertising industry.

The lawsuit alleges that Google monopolized – or attempted to monopolize – products and services used by advertisers and publishers in online display advertising. These anticompetitive practices demonstrably harmed publishers’ abilities to monetize content, increased advertisers’ costs to advertise and directly harmed consumers. The complaint also alleges that some of Google’s business tactics are misleading.

In October, Attorney General Hill joined a federal antitrust lawsuit against Google. Both lawsuits aim to limit Google’s monopolistic business practices in various online markets.

“It is time for Google’s reign as an untouchable tech monopoly to come to an end,” Attorney General Hill said. “Google’s anticompetitive online advertising practices harm everyone who isn’t Google, and we must do everything we can to level the playing field.”

Google’s monopolization of online display advertising includes an anticompetitive agreement with Facebook and suppressing competition in multiple relevant markets by a variety of other means, all of which harms consumers in violation of the antitrust laws, the attorneys general allege. In addition to representing both the buyers and sellers of online display advertising, Google competes directly against the buyers and sellers it separately represents, all while operating the largest exchange of those buyers and sellers.