The Role of the Department of Justice in Blocking Acquisitions


Staff member
May 18, 2022

The Role of the Department of Justice in Blocking Acquisitions​

The U.S. Department of Justice (DOJ) plays a crucial role in maintaining fair competition in the marketplace. One of its primary functions is to oversee and regulate mergers and acquisitions to prevent the formation of monopolies and protect consumer interests. This responsibility is managed through the Antitrust Division, which examines proposed mergers to ensure they do not stifle competition or harm consumers by creating or enhancing market power.

Notable Acquisitions Blocked by the DOJ​

1. AT&T and T-Mobile (2011): The DOJ blocked AT&T's $39 billion acquisition of T-Mobile, arguing that the merger would reduce competition in the wireless market and lead to higher prices for consumers.

2. Anthem and Cigna (2017): The proposed $54 billion merger between Anthem and Cigna, two of the largest health insurers in the U.S., was blocked by the DOJ. The department argued that the merger would reduce competition in the health insurance industry, leading to higher premiums and reduced innovation.

3. Comcast and Time Warner Cable (2015): The DOJ opposed the $45.2 billion merger between Comcast and Time Warner Cable, fearing that the combined company would wield too much power over the cable and broadband markets, potentially leading to higher prices and less choice for consumers.

4. Visa and Plaid (2020): Visa's $5.3 billion acquisition of fintech company Plaid was blocked by the DOJ. The department argued that the merger would limit competition in the payments market and stifle innovation in financial technology.

5. Lockheed Martin and Aerojet Rocketdyne (2022): The DOJ filed a lawsuit to block Lockheed Martin's $4.4 billion acquisition of Aerojet Rocketdyne, citing concerns that the merger would harm competition in the defense industry and lead to higher prices and reduced innovation.

Cybersecurity Concerns and Antitrust Regulations​

In recent years, the intersection of cybersecurity and antitrust regulation has become increasingly important. As technology companies grow in size and influence, concerns about cybersecurity and data privacy have come to the forefront. The DOJ's role in regulating mergers and acquisitions extends to ensuring that these companies do not become too powerful, potentially jeopardizing cybersecurity and consumer privacy.

The Fear of Monopoly in Cybersecurity​

The fear of monopolistic control in the cybersecurity industry is particularly acute because of the sensitive nature of the data involved and the critical importance of robust cybersecurity measures. If a single company were to dominate the cybersecurity market, it could lead to several potential issues:

1. Reduced Innovation: A monopoly in cybersecurity could stifle innovation, as the dominant company might have little incentive to improve its products or services.

2. Higher Costs: With less competition, prices for cybersecurity services could increase, making it more difficult for smaller businesses and individuals to afford necessary protections.

3. Vulnerability to Attacks: A monopolistic cybersecurity company could become a single point of failure, making it an attractive target for cybercriminals. A successful attack on such a company could have widespread and devastating effects.

4. Data Privacy Concerns: A single company controlling a large portion of the cybersecurity market might also control vast amounts of sensitive data, raising concerns about data privacy and the potential misuse of information.


The DOJ's efforts to block certain mergers and acquisitions are crucial for maintaining a competitive and fair marketplace. In the realm of cybersecurity, these efforts are particularly important to prevent the formation of monopolies that could stifle innovation, increase costs, and jeopardize data security. As technology continues to evolve, the DOJ's role in overseeing mergers and acquisitions will remain vital to protecting both consumers and the broader economy.