If you have ever played the game Monopoly it will come to no surprise the true meaning behind the name. A monopoly is "the exclusive possession or control of the supply of or trade in a commodity or service." Simply put, if one person or company controls the whole supply of a product, it holds a monopoly in that market. In the United States, a capitalist country, this is perfectly legal. However, monopoly power comes with many caveats.

What Antitrust Law is For / Sherman Act

Antitrust law is not set in place to protect competitors of major corporations. Instead it protects the process of competition, thereby protecting consumers. If one major corporation dominates purely by "being the best" and it plays by the rules in terms of pricing and quality regulations, then antitrust law can't hold it accountable, it has done no wrong. However, without competitive pressure, a monopolist can raise prices or let quality slide, because nothing forces it to do otherwise. The Sherman Act, introduced into law in 1890, was designed to terminate anticompetitive conduct. Later antitrust laws, the Clayton Act and the FTC Act, both passed in 1914, followed to address shortcomings in the Sherman Act.

Sherman Act, Sections 1 & 2

The Sherman Act, named for Senator John Sherman, contains two main sections regarding antitrust law, with the intent of upholding market competition among actors. Section 1 prohibits agreements that restrain trade; these might be contracts, conspiracies, or combinations between two or more parties. This covers price-fixing, market allocation, and other collusive conduct. A single firm acting unilaterally—on its own—can't violate Section 1, because there's no agreement between separate parties. Section 2 is where single actors can violate the Sherman Act, targeting monopolization. The word is narrower than it sounds. Having monopoly power is legal. Monopolizing means abusing that power to keep rivals out, and that is the crime.

Having monopoly power is legal. Monopolizing means abusing that power to keep rivals out, and that is the crime.

A company that dominates by building a better product has done nothing wrong. One that dominates by locking competitors out has. Cases Verizon v. Trinko and United States v. Grinnell set the precedent here; acquiring monopoly power through "superior product, business acumen, or historic accident" is legal; getting there through exclusionary conduct is not.

U.S. v. Google (Search Engine, Filed 2020, Decided 2024)

In 2020, the United States Department of Justice (DOJ) accused Google of illegally monopolizing the search engine market by means of exclusive contracts, violating section 2 of the Sherman Act. Google paid Apple and makers of Android devices billions, in exchange for Google's search engine being the primary search engine by default on their devices. All of this was unfolding while Google allegedly destroyed evidence and communicated through auto-delete chat systems. In 2024, Judge Mehta ruled this conduct to violate section 2 of the Sherman Act. Remedies required Google to no longer include search engines in exclusive contracts along with requiring Google to share certain search index data with competitors. However, Mehta rejected the DOJ's request for divestiture, a much stronger remedy. Google's search engine was not made primary because it was "the best;" companies were paid to do this act, this is what actually violates the Sherman Act.

Google's search engine was not made primary because it was 'the best'; companies were paid to do this act, this is what actually violates the Sherman Act.

As the first major big-tech monopolization case since Microsoft (2001), it sets an important marker for future enforcement.

U.S. v. Google (AdTech, Filed 2023, Decided 2025)

Before Google's 2020 search engine case came to a close, the DOJ accused Google of illegally monopolizing the advertising technology (adtech) market, this time violating both sections 1 and 2 of the Sherman Act. This case is far more complicated. Before diving in, understanding the adtech tools is critical. A Publisher is a site with ad space, normally a blog or website. Publisher ad servers are systems companies use to manage and sell their ad inventory across its buyers. Think of it like a control panel, it tracks everything the company needs to run effective ads across the internet; publishers use this to control their ad space. Ad exchange is a real-time marketplace that runs auctions connecting advertiser demand to publisher supply as a page loads. Think of an auction house but for online advertisement. Google was the only dominant actor to own both an ad server and an ad exchange, giving it enormous market power.

Auction-Rigging Mechanics

Google's publisher ad server is called DoubleClick for Publishers (DFP) and their Ad exchange is called AdX. The violation of the Sherman Act lies within Google's particular setup. In order to get AdX's bids into their auction, publishers had to run DFP as their ad server; this meant that control of the ad server gave Google leverage over who could even compete in the ad exchange. This leverage allowed Google a First Look and Last Look into ad bids, something companies only playing on one side simply can't do. A First Look allowed Google to use its ad server (DFP) to give its ad exchange (AdX) a first look into ad spots, if AdX wanted that spot at a fixed price offered by the publisher, it got it, no rival auction required. A Last Look allowed Google to know exactly how much money all the bids for an ad spot cost, since it owned an ad server (DFP). Given this, Google could make sure it provides an amount from their ad exchange that is more than the highest bid on other exchange platforms; that individual who placed the bid with Google's ad exchange gets their ad spot; Google gets a fee from being the middle man in this process.

Evidence

The DOJ made similar auto-delete chat allegations against Google in this 2023 AdTech case, claiming that Google had "history off" as the default setting for employee chats, deleting after 24-hours, unless manually overridden. Employees of Google were told to "think twice before you write about hot topics," which the DOJ argued showed intent to hide information. Judge Brinkema condemned the conduct but declined to sanction Google, since the surviving evidence was already enough to rule for the DOJ.

Rulings

In April 2025, Judge Brinkema issued her liability ruling. She found Google had illegally monopolized two markets, publisher ad servers (DFP) and ad exchanges (AdX), and had unlawfully tied those two products together in violation of Sections 1 and 2 of the Sherman Act. She rejected the government's remaining claims, finding it had not proven a separate market for advertiser tools and that Google's earlier acquisitions of DoubleClick and AdMeld were not anticompetitive. The result was a split decision: a decisive win for the government on Google's conduct, but not a clean sweep. After the rulings are decided, a separate proceeding follows to figure out remedies, in order to restore competition. Remedies primarily are tied to two types: behavioral and structural remedies. Behavioral remedies include rules the company must follow going forward, such as sharing data with rivals or submitting to a monitor; Google prefers this. More intense remedies include structural remedies, forcing the company to sell off parts of itself. As of this writing, the remedies trial has concluded, with the DOJ seeking a forced sale of AdX (and possibly DFP) and Google offering behavioral fixes, but Judge Brinkema has not yet issued a final remedies ruling.

Why This Matters

After examining these two Google antitrust law cases, regarding violations of the Sherman Act, it's clear the law is still sharp enough to catch and find large tech companies, like Google, in violation of the law. However, if remedy trials go on and on, oftentimes followed with appeals, currently happening in both Google cases, then what does the Sherman Act really do for the competitive market? Winning the case seems to come easily, but applying real remedies seems to come at a challenge. Monopoly isn't the crime in the Google case or similar cases, the conduct of acquiring and maintaining it is the true crime. Brinkema found the DoubleClick and AdMeld acquisitions legal. Google's size was never the violation, how it operated was. The 2020 Google Search case was a violation of Section 2. Google paid to lock rivals out of the doorway, halting competition. In the 2023 AdTech case, both Sections 1 and 2 were violated since there was tying (forcing buyers of one product to take the other) involved, plus illegal monopolization. Congress wrote the Sherman Act broadly and vaguely on purpose, leaving courts to define "restrain trade" and "monopolize" case by case, which results in arguments regarding what constitutes a violation, especially considering how far the United States has come since 1890. If a company can violate the Sherman Act, lose in court, and keep operating largely intact for a decade, what is the law actually deterring? Behavioral remedies aren't nothing, and market conditions can shift faster than litigation. But the gap between "found liable" and "anything changed" is the real story of modern antitrust.