On Saturday, The Wall Street Journal reported that investigators from the Department of Justice will examine “Google’s business practices related to its search and other businesses.” It’s one of the biggest threats Google has ever faced from US regulators, but so far, we don’t know much about the case itself. The Journal’s description was open-ended, and the nature of Google’s business makes it vulnerable to antitrust challenges from a number of different directions. Google dominates the search market, but it also holds nearly 40 percent of the digital advertising market, and Android is the world’s most popular operating system. In all of these markets, critics have claimed that Google is simply too big, and it’s faced billion-dollar fines over each of them in Europe.

The probe is supposedly in its early stages, and it’s not clear what the Justice Department might consider worth investigating. But the earlier EU fines, along with a 2013 Federal Trade Commission investigation, offer some guidance. We’ve broken down some of the major monopoly allegations against Google as well as how courts and regulators have treated them so far — from search engine rankings to Android app bundling. (Google, perhaps understandably, did not respond to a request for comment.)

GOOGLE HAS MONOPOLIZED AD PLACEMENT

Google is the biggest single player in online advertising: one forecast puts its market share at 37.2 percent in 2019, compared to around 22.1 percent for its closest rival, Facebook. It makes money on two fronts: advertisers can buy ad space through a Google exchange, and websites can serve Google ads through the AdSense program. It’s been accused of abusing its power on both sides of the transaction, which is something Google denies.

The European Commission has specifically investigated Google’s relationship with web publishers. In March, it found that Google had unfairly banned AdSense customers from placing other search engines and ad boxes on their sites. (Google phased out this clause, but it retained the right to “premium” ad space on websites until 2016.) Publishers had fewer options for selling their ad space as a result, potentially driving down their revenue. At the same time, anyone using Google’s ad placement service was also pushed toward using the search engine exclusively, making it harder for competitors like Bing to get off the ground. The EC court fined Google €1.49 billion, saying it had “cemented its dominance” through illegal means. “Google’s conduct harmed competition and consumers,” the court said, “and stifled innovation.”

The FTC also examined this policy, and although it cleared Google in 2013, investigators privately expressed serious concerns about the practice. Bloomberg has noted that AdSense is a declining part of Google’s business, and the company has changed its policies to avert some of the key complaints. But the Justice Department could still decide that these exclusivity deals helped Google — unfairly — reach its current level of power.

Read the full article on The Verge.