Cohen Milstein is recognized as one of the leading data breach plaintiff law firms in the United States, having played a leadership role in virtually every major data breach class action litigated to date. Relevant national rankings include:

In addition to spearheading cutting-edge litigation strategy, we are highly regarded by co-counsel and the judiciary alike for our collaborative efforts in pre-litigation investigations, working with top data privacy and economic experts, our ability to deftly handle complex discovery for large-scale data breach class actions, ensuring streamlined, efficiencies of scale, as well as our exceptional motion practice work.

We welcome co-counsel opportunities with other consumer protection law firms, nationwide.


We have the unique honor of being court-appointed as Lead, Co-Lead Counsel or serving as Steering Committee Counsel in numerous major data breach class action litigation in the United States.

Our Data Breach & Cybersecurity Litigation team is led by:

  • Andrew N. Friedman – With more than 35 years of experience litigating cutting-edge class actions, Mr. Friedman has led and co-led some of the most significant data privacy class actions in recent years, including In re Anthem, Inc. Data Breach Litig. (N.D. Cal.), where he aggressively prosecuted claims on behalf of the nearly 80 million consumers impacted by the massive data breach, his team took or defended nearly 200 depositions, reviewed 3.8 million pages of defendants’ documents, fully briefed class certification, and he was instrumental in negotiating the $115 million settlement fund, which at the time far exceeded any data breach settlement. In 2018, Mr. Friedman was ranked, Law360 “MVP – Cybersecurity and Privacy.”
  • Douglas J. McNamara – President of the American Association for Justice Class Action Litigation Group, Mr. McNamara specializes in litigating complex, nationwide and multi-state class action lawsuits. Mr. McNamara is also highly regarded for his thought leadership on such topics as federal preemption, class certification, and class action damage models, and is frequently appointed to class and MDL Plaintiffs’ Steering Committees and/or Expert Committees.

Members of our Data Breach & Cybersecurity Litigation team also include the former Deputy Associate Attorney General of the U.S. Department of Justice and former cybersecurity defense attorneys.

Representative Matters – Current Cases

  • In re: Marriott International Inc. Customer Data Security Breach Litigation (D. Md) –On February 21, 2020, the court largely denied Defendants’ motion to dismiss, allowing Plaintiffs claims to move forward in this data breach class action, which alleges that, by the Marriott’s own admission in November 2018, a data breach compromised the personal information of nearly 400 million customers who made reservations at Starwood-branded hotels., This constitutes one of the largest data breaches in U.S. history. In April 2019, Cohen Milstein’s Andrew N. Friedman was court appointed Consumer Plaintiffs’ Co-Lead Counsel to oversee the litigation.
  • In re MGM Resorts International Data Breach Litigation (D. Nev.) – On February 1, 2021, the court appointed Cohen Milstein’s Douglas J. McNamara as Co-Lead Interim Class Counsel in this consolidated data breach class action against MGM Resorts related to the July 2019 data breach of personal information of between 10.6 million and 142 million MGM resort guests and customers.
  • In Re: Blackbaud, Inc., Customer Data Breach Litigation (D.S.C.) – Cohen Milstein is representing plaintiffs in a putative data breach class action against Blackbaud, a cloud computing account management and billing services company for its failure to protect the personal information of its client customers, including hospital patient record information and social security numbers, during a data breach that started in February 2020. On February 16, 2021, Cohen Milstein’s Douglas J. McNamara was court-appointed to the Plaintiffs’ Steering Committee.
  • Facebook 2018 Data Breach Litigation (N.D. Cal.) – On November 16, 2020, the court preliminarily approved an injunctive relief settlement in this data breach class action against Facebook. Once finally approved, the injunctive relief settlement will require Facebook to adopt, implement, and/or maintain a detailed set of security commitments for the next five years, which will be independently assessed by a third-party. In February 2019, the court appointed Cohen Milstein’s Andrew N. Friedman Co-Interim Class Counsel to oversee the litigation

Representative Matters – Concluded Cases

  • In Re Anthem, Inc. Data Breach Litigation (N.D. Cal.) – On August 16, 2018, the Court granted final approval to a $115 million settlement – the largest data breach settlement in U.S. history at the time – ending claims that Anthem Inc., one of the nation’s largest for-profit managed health care companies, put 79 million consumers’ personal information, including social security numbers and health date, at risk in a 2015 data breach. Cohen Milstein’s Andrew N. Friedman was Co-Lead Counsel in this watershed nationwide class action.
  • In re Equifax, Inc., Customer Data Security Breach Litigation (N.D. Ga.) – On December 19, 2019 the court granted final approval a landmark $1.5 billion settlement concluding this data breach class action affecting more than 147 million people in the U.S. The settlement consists of a record-breaking $425 million in monetary and injunctive benefits and requires Equifax to spend $1 billion to upgrade its security and technology. In February 2018, Cohen Milstein Andrew N. Friedman was appointed to the Consumer Plaintiffs' Steering Committee.
  • Home Depot Data Breach Litigation (N.D. Ga.) – On September 22, 2017, the court granted final approval of a $25 million settlement, ending the class action arising out of the 2015 Home Depot data breach, a cyber-attack that affected hundreds of financial institutions and more than 40 million consumers who used their debit and credit cards to patronize Home Depot. Cohen Milstein’s Andrew N. Friedman was a member of the Plaintiffs’ Steering Committee representing financial institution plaintiffs and headed the Expert Committee.
  • In Re: Vizio, Inc., Consumer Privacy Litigation (C.D. Cal.) – On July 31, 2019, the court granted final approval of a $17 million settlement in this class action, which alleged that VIZIO secretly tracked — for 3 years — what people were watching on about 16 million smart TVs. Not only did VIZIO collect consumers’ viewing histories and information about their digital identities, according to the complaint, but also VIZIO sold that information to other companies without consumers’ consent. Cohen Milstein’s Andrew N. Friedman was a member of the Plaintiffs’ Steering Committee.