Marc A. Wallenstein
Marc A. Wallenstein is a partner at the firm and a former federal prosecutor. He has spent his career holding wrongdoers accountable, in both public service and private practice. Marc is an experienced courtroom advocate who has tried numerous cases to jury verdict. He is also undefeated before the United States Court of Appeals for the Ninth Circuit, having won all ten of the appeals in which he served as lead counsel.
Marc recently led a talented team of attorneys and staff to a $314 million jury verdict in Csupo v. Google, a class action against Google on behalf of approximately 13 million California Android users. Marc ran the case at all stages and tried the case to victory after more than five years of hard-fought litigation. The legal theories and evidence were developed independently, without relying on any prior government investigation or private litigation.
At the close of the trial, the presiding judge remarked: “This was a privilege. This was excellent lawyering. I think this Court has never seen the magnitude of lawyering that we’ve seen during this trial, so I want to thank you all.”
The Csupo case settled after trial for $350 million—more than the amount of the jury’s verdict. The presiding judge, in approving the settlement, wrote: “The undersigned can easily say that class counsel represented the class by applying a level of advocacy at the top tier of all counsel previously observed.”
Marc also leads a parallel lawsuit in federal court on behalf of Android users outside of California, Taylor v. Google. Marc won an appeal before the Ninth Circuit, reversing the district court’s dismissal of the complaint. Marc’s advocacy resulted in a unanimous decision issued just two weeks after oral argument. After remand, the trial court granted final approval to a proposed $135 million settlement.
Before joining Korein Tillery, Marc served for six years as an Assistant U.S. Attorney in the District of Hawaii. Among other matters, Marc successfully prosecuted the first terrorism case ever brought against an active-duty member of the U.S. military, culminating in a 25-year sentence. Marc obtained record fines in numerous environmental cases, including the largest marine pollution fine in District history.
At his final court appearance as a federal prosecutor, the presiding district judge remarked:
And I’d like to take this opportunity to thank Mr. Wallenstein for his service to this Court and to the District of Hawaii. We will miss you, and your representation has always vigorous and very fair with an eye to justice, which I'd like to say is typical of all U.S. Attorneys, but is not, and so I mostly appreciate your personal talents but also your consistent value of ensuring a just outcome. We will particularly miss your baritone voice. But I’m sure that you’ll go on to great success in private practice, and I hope that you’ll return often to visit or perhaps appear in the District of Hawaii. But thank you very much for your service.
Prior to his time at the Department of Justice, Marc served for three years as a Prosecutor at the Office of the Chief Prosecutor of Military Commissions, United States Department of Defense. Marc prosecuted violations of the law of war committed by enemy alien belligerents before a military commission in Guantanamo Bay, Cuba. Marc served as a litigation team chief, managing attorneys, paralegals, FBI agents, analysts, and staff. Marc also served as an appellate and pretrial motions attorney on a range of cases, including the prosecution of Khalid Shaikh Mohammed and four others accused of perpetrating the attacks of September 11, 2001.
Marc successfully maintained an active Top Secret/SCI security clearance for a decade throughout his federal employment.
Marc is a graduate of Harvard College (2002) and Yale Law School (2006). After law school, he served as a law clerk in the Southern District of New York and on the United States Court of Appeals for the Ninth Circuit.
Marc is admitted to practice law in New York, Washington DC, Texas, Hawaii, Connecticut, Oregon, and numerous federal district and circuit courts around the country.
For more information about Marc, including representative matters, please click below.
Representative Matters
At Korein Tillery, Marc served as trial counsel for thousands of minor league baseball players who won the right to be paid minimum wage by Major League Baseball, in Senne v. MLB. The lawsuit reached a landmark $185 million settlement on the eve of trial, which represented 137% of the unpaid wages owed to class members. The trial court wrote that counsel “has handled this case skillfully and with professionalism, diligently pursuing the interests of the players. The significant relief they have obtained under the Settlement Agreement is, in no small part, due to their expertise and dedication.”
Marc served as part of the co-lead counsel teams in two additional cases against Google. Marc took numerous depositions leading up to a proposed $700 million settlement-in-principle, in a lawsuit challenging Google’s anticompetitive practices regarding the fees it charges to developers of apps distributed through the Google Play Store. And Marc pursued antitrust claims against Google arising out of its monopolization of the online advertising market, in which Google acts as the buyer’s agent, the seller’s agent, and the marketplace, all at the same time.
At the U.S. Attorney’s Office, Marc gained expertise in matters involving national security, financial crime, procurement fraud, health care fraud, real estate fraud, public corruption, cybercrime, environmental crime, and crimes against children. Marc obtained the largest monetary penalty ever imposed in a criminal shark fin trafficking case in the United States. Marc served as Anti-Terrorism Advisory Coordinator (ATAC), responsible for national security investigations and prosecutions; as Computer Hacking and Intellectual Property (CHIP) Coordinator, responsible for complex issues related to computer crime and electronically stored information; as the as the National Parks coordinator; and as a member of the Department of Justice’s Cryptocurrency Working Group. Marc has received several awards from the Department of Justice and the Federal Bureau of Investigation for his work and has taught national security investigations and prosecutions to fellow prosecutors and agents at the Department of Justice's National Advocacy Center.
Marc previously conducted complex civil litigation in Washington DC at a boutique litigation firm. Among other matters, he represented the National Credit Union Administration—an independent federal government agency—against Wall Street banks for failed investments in residential mortgage-backed securities, with co-counsel from Korein Tillery. The two firms ultimately recovered $5.1 billion. Marc also managed a non-intervened qui tam lawsuit against the world's largest biotechnology company, which resulted in a $762 million global settlement on the eve of the trial.
In his spare time, Marc has taught trial practice at Yale Law School.