Ben Thomassen


I graduated summa cum laude with a degree in philosophy from St. Mary’s College of Maryland and received my J.D. magna cum laude from the Illinois Institute of Technology Chicago-Kent College of Law. I focus on privacy-related class actions.

  • Favorite Emoji
  • Desired Superpower
  • Cups of Coffee 4
  • How I Get Around

Who would play you in a movie about you?


My little brother Mike, because that would be hilarious.

Curriculum Vitae

BEN THOMASSEN is Counsel at Edelson PC and a member of the firm’s Issues & Appeals Group. He regularly litigates complex issues—often ones of first impression—in trial and appellate courts, has been appointed as class counsel for numerous certified federal classes, and has played key roles in industry-changing cases that have secured millions of dollars of relief for consumers. Ben has briefed and orally argued appeals in state and federal appellate courts, including—most recently—before the Illinois Supreme Court. In additional to achieving landmark appellate rulings and strong results for his clients, Ben has been recognized for “display[ing] an extraordinary measure of excellence and courtesy that is unfortunately all too rare in today’s fractious and overly competitive atmosphere.” Dancel v. Groupon, Inc., No. 1:18-cv-02027, dkt. 212 (N.D. Ill. Mar. 25, 2021) (Cole, Mag. J.).


Substantively, Ben’s work has focused primarily on issues concerning data privacy/security and technology. Among other cases, claims, and issues, this includes data breach litigation, cases alleging statutory causes of action (including claims brought under state and federal wiretapping statutes, the Illinois Biometric Privacy Act, state right of publicity statutes, and other state and federal consumer privacy statutes), and various consumer fraud issues (including, for example, ones arising in the cryptocurrency and consumer technology spaces).


Representative Plaintiffs’ Class Actions:

  • Resnick, et al. v. AvMed, Inc., No. 10-cv-24513 (S.D. Fla.). Presented oral argument to Eleventh Circuit Court of Appeals in data breach case, which secured reversal and resulted in landmark appellate decision endorsing common law unjust enrichment theory, irrespective of whether identity theft occurred. Case also resulted in the first class action settlement in the country to provide data breach victims with monetary payments irrespective of identity theft.
  • In re Advocate Data Breach Litigation, No. 2013-CV-20390 (Cook County, Illinois). Briefed, argued, and secured reversal in first data breach case heard by Illinois’s First District Appellate Court.
  • Part of the team representing the City of Chicago in the Marriott data breach litigation, which concerns a massive data breach affecting 383 million hotel guests. In re Marriott International, Inc., Customer Data Security Breach Litigation, MDL 2879 (D. Md.).
  • West Bend Mutual Insurance Co. v. Krishna Schaumburg Tan, Inc. and Klaudia Sekura, 2021 IL 125978.  Briefed, argued, and won appeals in first-of-its-kind insurance coverage dispute for claims brought under the Illinois Biometric Privacy Act, 740 ILCS 14/1, et seq. before the First Appellate District Court and Illinois Supreme Court.
  • In re: National Collegiate Athletic Association Student-Athlete Concussion Litigation, No. 13-cv-09116 (N.D. Ill.). Represented objector student athlete in concussion multidistrict litigation. Secured student athletes’ ability to bring class litigation against the NCAA, athletic conferences, and institutions for injuries resulting from head injuries.
  • Harris v. comScore, Inc., No. 11-cv-5807 (N.D. Ill.). Achieved adversarial certification of a massive class in privacy case accusing Internet analytics company of improper data collection practices. Resulted in landmark $14 million class settlement.
  • Dickey, et al. v. Advanced Micro Devices, Inc., No. 15-cv-04922 (N.D. Cal.). Litigated consumer fraud case against multinational semiconductor company. Secured key substantive and choice of law rulings, which paved the way for certified national class of computer processor purchasers.
  • Michigan Preservation of Personal Privacy Act cases (various). Litigated multiple privacy cases accusing national magazine publishers of unlawfully disclosing subscribers’ personal information. Resulted in multiple class settlements securing tens of millions of dollars for consumers.



  • Illinois
  • United States Court of Appeals for the Ninth Circuit
  • United States Court of Appeals for the Seventh Circuit
  • United States District Court for the Northern District of Illinois, Eastern District of Michigan, District of Colorado, and District of New Mexico.



  • Selected as an Illinois Emerging Lawyer by Leading Lawyers (2017, 2018)
  • Order of the Coif (2011)
  • Received seven CALI awards in law school (Appellate Advocacy, Business Organizations, Conflict of Laws, Family Law, Personal Income Tax, Property, and Torts)



Before settling into his legal career, Ben worked in and around the Chicago and Washington, D.C. areas in a number of capacities, including stints as a website designer/developer, a regular contributor to a monthly Capitol Hill newspaper, and a film projectionist and media technician for commercial theatres, museums, and educational institutions. Ben received a Master of Arts degree from the University of Chicago.


During law school, Ben earned a certificate in Litigation and Alternative Dispute Resolution, served as Vice President of Chicago-Kent’s Moot Court Honor Society, and spent his two summers as a law clerk for the Cook County State’s Attorney and Corporation Counsel for the City of Chicago.

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