The Justice Department’s antitrust case against Google and its search engine dominance is set to begin Tuesday. 

The case, U.S. et al v. Google, focuses on the company’s popular search engine, alleging Google used its 90% market share to illegally throttle competition in both search and search advertising.

This is one of several antitrust cases against the company. In January, the DOJ filed an antitrust case against it concerning Google’s role as an advertising broker, publisher and auctioneer.

The charges. The federal government alleges Google is harming consumers by stifling innovation in online search tools and limiting choice.

The DOJ also says Google has been able to maintain its monopoly over online search through exclusive agreements that preinstall its search application on devices. This, the government alleges, allowed Google to become the dominant search engine over its rivals and stifle competition.

Federal prosecutors are likely to argue that Google is not allowing a free market of rivals who could offer search choices with better technical perks — such as the speed at which search results are presented — and on policy choices, such as more stringent data privacy practices.

The defense. Google has pushed back strongly on the allegations of anticompetitive behavior. Its products and services are more popular because they are simply better, not because Google has tilted the playing field away from potential rivals, the company will argue.

Google is also expected to argue that their contracts to be default search engines on browsers are not exclusive and do not limit competition. The company argues that users can easily set a new default search engine and that their contracts do not limit access to other search options.

Dig deeper. Report: Google sharing Chrome iOS search revenue with Apple

Why we care. A big change at Google could cause big changes throughout the digital marketing ecosystem. If the DOJ proves its case and somehow alters Google’s search stranglehold it might mean lower costs for advertisers. If Google wins more tech regulation may be harder to achieve. Time, as always, will tell.

Dig deeper. US Justice Department sues Google again, aims to dismantle its ad division

What’s at stake. The U.S. and state allies are not seeking a monetary penalty, but rather an injunction barring Google from continuing the alleged anticompetitive practices. Such an order could have significant business implications for Google. For example:

• The government said in its lawsuit that the court could break up the company as a fix.
• More broadly, the Justice Department may argue it wants to stop Google from leveraging its alleged search monopoly to make exclusive deals in newly emerging markets, including artificial intelligence.

The case is widely seen as one of the biggest challenges to tech industry power since the DOJ sued Microsoft in 1998 over its market dominance for personal computers. The trial court in that case found Microsoft unlawfully tried to block rival browser Netscape Navigator. Microsoft later reached a settlement that left the company intact.

Dig deeper. Judge: No evidence Google harmed competitors by limiting search visibility