Ariana Tadler


Practice Areas:
Contact Information:
Phone: 212-946-9453

B.A., Hamilton College, 1989
J.D., Fordham University School of Law, 1992

Bar Admissions:
New Jersey, 1992, New York, 1993
"Working for consumers and investors who have suffered a financial loss or wrong has been very appealing to me. Doing what I can to rectify some of the inequities in the lives of individuals or groups of people is gratifying, particularly in very large, complex cases . . . . I also enjoy cases that are not just about the recovery of monies lost but that also play a role in changing practices that companies engage in that are unfair to consumers and investors.” —Ariana J. Tadler, Lawdragon 500

Ariana Tadler, Managing Partner at Milberg Tadler Phillips Grossman LLP, has over twenty-six years of experience litigating and managing complex securities, consumer, and data breach class actions. She has litigated numerous high profile, fast-paced cases, requiring unique legal and technological acumen and case management skills as well as endurance and agility.

Ms. Tadler is recognized as one of the nation’s leading authorities on electronic discovery, and pioneered the establishment of an E-Discovery Practice group within a plaintiffs’ firm structure more than 15 years ago. She is the only plaintiffs’ lawyer to repeatedly be ranked as a Band 1 E-Discovery Practitioner by Chambers and Partners in the Global-USA and USA-Nationwide categories. Her exceptional skills and knowledge in the field of E-Discovery have distinguished her among her litigation peers, uniquely positioning her in leadership roles in some of the most significant litigations of the decade.

Ms. Tadler was recently appointed by United States Supreme Court Chief Justice John Roberts to serve on the Federal Civil Rules Advisory Committee. Additionally, she has been appointed by Committee Chair, Judge John D. Bates, to the subcommittee tasked with reviewing and considering potential civil rules for multidistrict litigation (MDL) cases.

Ms. Tadler is described in Chambers USA 2017 as “a leading light in the plaintiffs’ Bar for e-discovery work, with interviewees labeling her ‘a vigorous opponent and very effective advocate because she has credibility with judges.’” She is frequently called upon for high-stakes litigation matters, with recent experience in a range of data breach, consumer and securities disputes. Sources also reported that “‘she is definitely a thought leader’ who ‘understands the technical issues and the language involved’ and is ‘a good statesman for the plaintiffs’ Bar because she's respected by the defense Bar.’” In 2018, Chambers USA reported: “The ‘very knowledgeable and experienced’ Ariana Tadler is regarded as a luminary of the plaintiffs' Bar. She draws plaudits for her shaping of the wider theoretical boundaries of the e-discovery field, particularly in the capacity of contributor to the Civil Rules Advisory Committee.” Most recently, in 2019, Chambers USA reported that market commentators described Ms. Tadler as “an absolutely first-rate practitioner, as well as being a remarkable consensus-builder under difficult circumstances” and stated that she “stands out as a practitioner with excellent knowledge and skilled application as a litigator with specific expertise in that combination of e-discovery, data privacy and security, and information governance.”

An AV® Preeminent rated (Martindale Hubbell’s highest rating) lawyer, Ms. Tadler continues to be recognized for her litigation prowess by prominent legal industry rating organizations. Ms. Tadler’s recent accolades include Band 1 (highest) recognition by Chambers and Partners for E-Discovery (2017-2019)(the only plaintiffs’ lawyer ranked among all 4 Bands); Super Lawyers 2018 “Top 50 Women Lawyers in New York Metro Area”(5th consecutive year)(Editor’s Note: “Attorneys like Ariana J. Tadler are recognized by their peers for their outstanding work and commitment to the spirit of the legal profession.”); Super Lawyers Top Rated Securities Litigation Attorney in New York (2010-2018); Super Lawyers 2017 “Top 100 Lawyers in New York Metro Area”; and Who’s Who Legal Litigation: Leading Practitioner-E-Discovery (2017). The Legal 500 2016 rankings stated: “‘Consummate professional’ Ariana Tadler, who leads the E-Discovery unit … is ‘exceptional, clear and forceful, a giant in her field’ … ‘able to navigate technical discovery issues at a very high level.’”


• Plaintiffs’ Interim Co-Class Counsel, Echavarria v. Facebook, Inc. Appointed Co-Interim Class Counsel by the Honorable William Alsup of the United States District Court for the Northern District of California in this putative nationwide class action against Facebook for a breach of personal data that according to Facebook was the result of a software vulnerability that existed for over a year (July 2017 – September 2018). In addition to her overall case leadership role, Ms. Tadler and her team are directly responsible for leading discovery in this litigation. A consolidated complaint was filed in the action on February 7, 2019.

• Plaintiffs’ Executive Committee, In re Apple Inc. Device Performance Litigation. Appointed to co-lead the Offensive Discovery and ESI Coordination Committee. Ms. Tadler and her team are responsible for drafting and negotiating discovery requests, protocols, search methodology and disputes, including by negotiation and/or motion practice.

• Plaintiffs’ Steering Committee, In re Equifax, Inc. Customer Data Breach Litigation. Ms. Tadler and her team are directly responsible for drafting and negotiating discovery requests, protocols, search methodology, and resolving disputes, including by negotiation and/or motion practice.

• Plaintiffs’ Executive Committee, In re: Yahoo! Inc. Customer Data Breach Security Litigation.Ms. Tadler is one of five court-appointed members of the Plaintiffs’ Executive Committee in the Yahoo! data breach litigation, a class action arising from a breach affecting more than 3 billion Yahoo! user accounts. The firm’s team, under Ms. Tadler’s direction, wasprimarily responsible for the massive and complex discovery in the case. To date, Ms. Tadler’s team has taken the lead in drafting and negotiating extensive formal requests for Production of Documents, as well as negotiating a series of discovery-related orders entered by the Court, including a protective order, E-Discovery protocol, “Rule 502” order governing the inadvertent production of privileged materials, and ESI Search Protocol. Ms. Tadler’s team also supervised the review of case documents and integrated the application of advanced technological stepsto facilitate efficient review.

• Plaintiffs’ Steering Committee, In re Target Corporation Customer Data Security Breach Litigation.Represented consumers in a class action accusing Target Corp. of failing to protect customers from a massive data breach during the holiday shopping season. ($10 million settlement.)

• Plaintiffs’ Executive Committee, In re Intuit Data Litigation.Appointed to the Plaintiffs’ Executive Committee in a class action alleging that Intuit failed to take adequate measures to prevent fraudulent tax return filings through the popular TurboTax program, Ms. Tadler and her team were instrumental in the negotiation of an ESI Protocol and other agreements on the parameters of discovery, and continued to play an influential role in the ongoing litigation, including through resolution by settlement. (Settlement pending final approval.)

• Plaintiffs’ Counsel, Torres, et al., v. Wendy’s International LLC. Lead counsel sought out Ms. Tadler and her team to represent consumers and facilitate discovery and other aspects of litigation in a class action accusing Wendy’s of failing to protect customers from a massive data breach occurring via point of sales systems at more than 1,000 of its franchised restaurants. (Resolved by settlement.)

• Lead Counsel, In re ConAgra Foods, Inc. and In re General Mills, Inc. Kix Cereal Litigation.Representing classes of consumers in cases involving the alleged misrepresentation of GMO food products as “all natural”; the cases involve front-line legal issues, cutting-edge discovery negotiations and complex disputes and motions. In In re Conagra Foods, Inc., the team was successful in achieving class certification by the district court, which was affirmed by the Court of Appeals for the Ninth Circuit and survived a petition for a writ of certiorari to the United States Supreme Court by defendants.

• Plaintiffs’ Co-Lead Counsel, In re ARIAD Pharmaceuticals Securities Litigation.Ms. Tadler and her team represented investors in a securities fraud class action accusing ARIAD of making materially false and misleading statements regarding the safety and potential success of the company’s proprietary chronic myeloid leukemia drug, despite knowledge that patients in company-sponsored clinical trials were suffering an array of dangerous side effects that risked patient safety and impacted the likelihood that the drug would receive FDA approval. ($3.5 million settlement).

• Lead Counsel, Ener1 v. PricewaterhouseCoopers.Ms. Tadler represented an alternative energy company in its claims of negligence against one of the Big 4 accounting firms. (Case settled on confidential terms.)

• Special Discovery Counsel, Republic of Colombia, et al. v. Diageo North America, Inc.Ms. Tadler and her team at Milberg LLP represented the government of Colombia, serving as Special Discovery Counsel, in its pursuit of claims alleging smuggling and illegal sales of alcohol by several international companies for violation of United States RICO statutes and other common law claims. Engagement encompassed identifying relevant information responsive to defendants’ requests, confirming and guiding preservation practices, and interviewing and collecting data from more than 100 custodians in 23 Colombian Departments (Colombia’s equivalent to our States in the U.S.). Team also reviewed and produced data in the ongoing litigation, and was tasked with ensuring compliance with the various privacy laws of Colombia and the United States with regard to personal data, controlled data and the transfer of sensitive information.

• Plaintiffs’ Liaison Counsel (court-appointed), Lead Counsel and Executive Committee Member, Initial Public Offering Securities Litigation.Represented investors in 300+ securities class actions alleging a market manipulation scheme involving hundreds of initial public offerings and 55 prominent defendant investment banks. Through aggressive litigation, plaintiffs’ counsel obtained a settlement totaling $586 million. This case is notable for the unique strategies that were employed to manage this mammoth litigation. Ms. Tadler and her team were at the forefront of dealing with complex discovery issues and crafted innovative tools to streamline the process. As a member of the court-appointed Plaintiffs’ Executive Committee, and as a court-appointed liaison counsel, while at Milberg LLP, Ms. Tadler oversaw the efforts of approximately 60 plaintiffs’ firms in combating some of the most well-respected defense firms in the nation. The case was so large and included such extensive discovery that it required its own off-site headquarters, including approximately 100 personnel from various firms dedicated solely to the prosecution of the matter and supervised and managed, in substantial part, by Milberg LLP personnel.

• Lead Counsel, In re MicroStrategy Securities Litigation.One of three cases litigated in the Eastern District of Virginia (a/k/a the “Rocket Docket”) in less than four years. Negotiated settlements valued at more than $150 million.


• Martindale Hubbell AV® Preeminent (highest rating)
• American Bar Association’s Legal Technology Resource Center’s (LTRC) Women of Legal Tech (2017)
• Super Lawyers “Top 50 Women Attorneys in New York Metro Area” (2014-2018)
• Super Lawyers “Top 100 Overall Lawyer in New York City” (2017)
• Super Lawyers (2010-2018)
• Chambers USA: Nationwide, Litigation: E-Discovery (2015-2019)
• Chambers Global Guide: Leading Lawyers in E-Discovery (2015-2019)
• Who’s Who Legal Litigation: Leading Practitioner-E-Discovery (2015-2016)
• Benchmark Litigation: Star (2015)
• Benchmark Top 250 Women Litigators (2014)
• ALM: 2014 Women Leaders in the Law (2014)
• Chambers USA: America’s Leading Lawyers for Business (2014)
• Lawdragon 500 (2009-13)
• Fellow of the Litigation Counsel of America


• American Association for Justice, Leaders Forum
• American Bar Association, Member
• American Bar Foundation, Life Fellow
• American Constitution Society for Law and Policy, Member
• Bloomberg Law Litigation Innovation Board, Member
• Federal Bar Council, Member
• Fordham Law Small to Midsize Law Firm, Advisory Council
• Georgetown University Law Center Advanced E-Discovery Institute, Advisory Board Member
• Mobilization for Justice (fka MFY Legal Services Inc.), Past Chair (2008-2010), Board Member
• National Association of Consumer Advocates, Working Member
• The National Association of Consumer Advocates, Member
• New York State Bar Association, Member
• New York Women’s Bar Association, Member
• Pound Civil Justice Institute, Member Fellow
• Seventh Circuit, Electronic Discovery Pilot Program
• The New York Inn of Court, Vice President (term 2016-2018)
• The Sedona Conference® (the leading “think-tank” on e-discovery), Board of Directors (2013-2017); Chair Emeritus (and Past Chair, 2007-2012), Steering Committee for Working Group 1 on Electronic Document Retention and Production
• Women's Bar Association of the State of New York, Member
• Women To Know, Advisory Board


• Presenter, “The Great Debate: In re Fried Chicken, Order of Special Master Regarding ESI Search Methodologies,” Georgetown Law CLE: 2018 Advanced eDiscovery Institute (“AEDI”), November 15, 2018.

• Presenter, “Crafting the 30(b)(6) Notice,” AAJ: Advanced 30(b) Seminar: The Most Powerful and Underutilized Tool, November 7, 2018.

• Presenter, “Big Challenges in the City of Big Shoulders.” Electronic Discovery’s Rise to Prominence,” American Bar Association: 2018 National Institute on Class Actions Agenda, October 18, 2018.

• Presenter, “Discovery in the Digital Age,” Advocacy Track: Using Critical Thinking to Develop Your Discovery Plan, AAJ 2018 Annual Convention, July 2018.

• Presenter, “May it Please the Court: Winning Arguments Before a Judge With Little or no ESI Experience,” e-Discovery for Trial Lawyers, State Bar of Georgia, June 2018.

• Presenter, “If You Must: Getting the Most from Search Terms While Preventing the Opposition From Hiding the Ball,” e-Discovery for Trial Lawyers, State Bar of Georgia, June 2018.

• Presenter, “The Critical Importance of the Rule 26 Conference or its Equivalent: What You Must Do,” e-Discovery for Trial Lawyers, State Bar of Georgia, June 2018.

• Presenter, “They’ve Been Served: What Should Go Out with Your Complaint and How to Handle the Initial Stages of Your Lawsuit,” e-Discovery for Trial Lawyers, State Bar of Georgia, June 2018

• Presenter, “The Importance of e-Discovery in Your Practice,” e-Discovery for Trial Lawyers, State Bar of Georgia, June 20128.

• Presenter, “Current Defense Tactics to Challenge Class Representatives and Class Counsel,” Consumer Attorneys of California: Class Actions and Mass Torts, June 2018.

• Presenter, “30(b)(6) Corporate Depositions,” American Association for Justice: New Lawyers’ Division, May 2018.

• Presenter, “Discovery Under (26)(b)(1): Proportionality,” HB Litigation: Class Action Mastery, May 2018.

• Presenter, “Best Practices for Handling Massive Troves of Sensitive Data,” Mass Torts Judicial Forum with the Hon. Marina Corodemus (ret.) - Cybersecurity in Mass Tort Cases, April 2018.

• Presenter, Electronic Discovery for the Plaintiffs’ Class Action Lawyer,” 360 Advocacy: Class Action Roundtable, April 2018.

• Presenter, “Theories for Presenting Class Actions in the Opioid Litigation,” Harris Martin: Opioid Conference, March 2018.

• Presenter, “Current Class Action Landscape in Opioids Multidistrict Litigation,” HB Litigation: Opioid Crisis – Claims, Damages & Science, January 2018.

• Presenter, “Class Treatment: Can These Claims be Resolved as a Class Action?” American Association for Justice: Opioid Litigation Seminar, September 2017.

• Presenter, “Are You Going to Eat That? Issues, Hurdles and Opportunities in Food and Supplement Litigation,” 26th Annual Spring CLE Meeting for the American Bar Association Tort and Insurance Practice Section (TIPS), Toxic Torts and Environmental Law Committee, April 2017.