The mass arbitration ecosystem spans plaintiff firms that pioneered the strategy, defense firms pushing back, and forums reshaping the rules of the road. What strikes me looking at this landscape: the plaintiff-side arms race is primarily a technology race — whoever builds the better intake machine wins.
Plaintiffs' FirmKeller Postman LLC
The defining firm of the mass arbitration era. Warren Postman built a tech-enabled mass action infrastructure for client intake and claim coordination at unprecedented scale. Campaigns against Amazon, TurboTax, DoorDash, and Samsung redefined the practice.
Amazon dropped its mandatory arbitration clause after 75,000+ demands filed over Alexa recordings.
Mass Arbitration Practice →
Plaintiffs' Firm
$250M+ RECOVERED
Milberg Coleman Bryson Phillips Grossman PLLC
Founded in 1965, Milberg is the most prominent mass arbitration firm by Google search visibility and one of the few with a dedicated Mass Arbitration Practice Group. Led by Senior Partner Gary Klinger and Partner Melissa Nafash, the group has recovered more than $250 million for consumers through ADR. Active in BIPA, CCPA, TCPA, GDPR, consumer fraud, antitrust, and financial services campaigns.
$64.5M — Parris v. Meta Platforms — 4M consumers, 100,000+ demands
$35M — Boone v. Snap, Inc. — 3M consumers, 10,000+ demands
1M+ claimants — Altice USA / Optimum arbitration (active 2025)
Practice leaders: Gary Klinger (Chicago) · Melissa Nafash (New York)
Mass Arbitration Practice →
Plaintiffs' Firm
$45B+ OVERALL
Edelson PC
Founded in Chicago by Jay Edelson in 2007, Edelson PC pioneered electronic privacy class action litigation. Named by Law360 as the only plaintiff's firm under 500 attorneys to earn Illinois Powerhouse status. Active in mass arbitration, BIPA, AI harm litigation, and public client enforcement actions.
$650M — Facebook BIPA — largest single-state privacy settlement ever
$925M — ViSalus jury verdict — largest privacy verdict in U.S. history
$76M — TCPA — largest Telephone Consumer Protection Act settlement
Founder: Jay Edelson · Chicago, San Francisco, D.C., L.A., Boulder
Firm Practice Areas →
Plaintiffs' FirmLichten & Liss-Riordan, P.C.
Shannon Liss-Riordan is credited as the pioneer of modern mass arbitration, developing the strategy against gig economy employers two decades ago. Major campaigns against Starbucks, FedEx, American Airlines, Uber, and Twitter/X. Forbes Top 200 Lawyers 2024 & 2025.
Campaigns against Twitter/X after Elon Musk layoffs generated hundreds of millions in potential liability.
Shannon Liss-Riordan →
Plaintiffs' FirmLabaton Keller Sucharow
Active plaintiff-side firm partnering with Keller Postman and Milberg on high-profile campaigns including streaming services Warner, Discovery, and Meta Instagram addiction. Active in consumer protection and securities-adjacent arbitration.
Partnered with Milberg to threaten Meta with mass arbitration — prompting Meta to remove its mandatory arbitration clause entirely.
Labaton.com →
Plaintiffs' FirmConsovoy McCarthy PLLC
Filed 19,541 concurrent demands against Sega under California's Unruh Civil Rights Act, triggering a $39M JAMS invoice and landmark counter-suit. Increasingly active using state privacy statutes as the basis for mass campaigns.
Sega lawsuit against Consovoy & JAMS is a bellwether case for forum liability — Virginia federal case survived motion to dismiss.
ConsovoymcCarthy.com →
Plaintiffs' FirmZimmerman Reed LLP
National plaintiffs' firm active in both class actions and mass arbitration. Faced counter-suit from L'Occitane over 3,144 privacy arbitration demands, and named in WarnerMedia's petition over alleged ethical violations in coordinated campaigns.
L'Occitane and WarnerMedia suits against Zimmerman Reed are leading test cases for corporate pushback against plaintiffs' firms.
ZimmReed.com →
Plaintiffs' Firm
LEGALTECH INNOVATOR
Kind Law
Las Vegas-based consumer protection firm founded by Michael Kind, widely recognized as one of the field's leading process and technology innovators. Kind Law co-founded MassArbCon — the only dedicated mass arbitration industry conference. Sued by sweepstakes company Zula in 2024 — D.C. court dismissed for lack of jurisdiction.
Co-founder of MassArbCon — the industry's definitive annual conference for mass arbitration practitioners.
ForumAmerican Arbitration Association (AAA)
The largest and most active forum for mass arbitration — 280,000+ individual claims in 2024. Major rule overhauls in 2024 and May 2025. In September 2025 launched an AI arbitrator for construction cases with expansion planned for 2026. Hosted a major employment mass arbitration CLE with NYU Law in March 2026.
Threshold: 25+ coordinated claims
AAA Mass Arbitration Rules →
ForumJAMS
Second major forum with a higher threshold of 75+ claims and distinct fee structure. Introduced mass arbitration rules in May 2024. Currently a defendant in the Sega counter-suit over $39M in initiation fees. The 9th Circuit upheld JAMS's authority to consolidate 7,300 simultaneous claims in Jones v. Starz Entertainment — a significant win for JAMS's procedural autonomy.
Threshold: 75+ coordinated claims · Consolidation authority affirmed by 9th Circuit 2025
JAMS Mass Arbitration Rules →
ForumNew Era ADR
Emerging alternative forum offering subscription-based pricing to neutralize per-case fee leverage, with a bellwether process for mass arbitrations. Live Nation's attempt to switch to New Era instead of JAMS was struck down as unconscionable by the 9th Circuit in Heckman v. Live Nation (2024).
Subscription model — enforceability of switch-to-New-Era clauses remains contested after Heckman ruling.
NewEraADR.com →
Defense FirmO'Melveny & Myers LLP
Leading defense-side firm advising major corporations on bellwether provisions, retroactive clause modifications, and responses to coordinated filings. Publishes the definitive annual mass arbitration year-in-review. Their 2025 review identifies bellwether enforceability and retroactive clause application as the two most consequential developments for corporate defendants.
Published definitive 2025 mass arbitration year-in-review — Jan. 2026.
2025 Year in Review →