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. 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. 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.