Los Angeles Office

Class Action & TCPA Defense in Los Angeles:
California State Courts, Federal Districts, & the Ninth Circuit.

Watstein Terepka LLP's Los Angeles office defends class action, TCPA, privacy, false advertising, and intellectual property litigation in California state courts, all four California federal districts, and the U.S. Court of Appeals for the Ninth Circuit.

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Map of California showing Watstein Terepka's Los Angeles office location An outline of the state of California in gold, with a glowing pin marking the Watstein Terepka LLP office at 515 South Flower Street, 19th Floor, in downtown Los Angeles. San Francisco San Diego Los Angeles Office Watstein Terepka LLP 515 South Flower St., 19th Fl. Los Angeles, CA 90071
Los Angeles Office

Watstein Terepka's Los Angeles Office at a Glance

The Los Angeles office of Watstein Terepka LLP sits in the downtown financial district at 515 South Flower Street, two blocks from the U.S. District Court for the Central District of California and minutes from the Ninth Circuit. The office was founded by partner Nathaniel Haas to serve the firm's California and West Coast defense practice.

Address
515 South Flower Street
19th Floor
Los Angeles, CA 90071
Get directions →
Phone
(213) 526-1880
Partner-led engagement on California matters.
Office Hours
Monday – Friday
8:00 a.m. – 6:00 p.m. PT
Urgent matters handled after hours.

A California Defense Practice Built for the Plaintiffs' Bar's Most Active Forum

California is the most active class action and privacy litigation jurisdiction in the United States. The state’s consumer protection regime — built on the Unfair Competition Law (Cal. Bus. & Prof. Code § 17200), the Consumer Legal Remedies Act, the Invasion of Privacy Act, and the California Consumer Privacy Act — creates statutory frameworks that plaintiffs’ firms use to convert ordinary business conduct into bet-the-company litigation.

Watstein Terepka’s Los Angeles practice was built specifically for this environment. The office handles class certification fights in the California federal districts, CIPA and CCPA defense, false advertising and IP claims, and Ninth Circuit appeals. Partners are admitted in California state and federal courts and have appeared as lead counsel in matters that have produced published Ninth Circuit opinions.

The California Legal Landscape We Defend

  • California Invasion of Privacy Act (CIPA). Cal. Penal Code §§ 630–638. Pen register and trap-and-trace theories under § 638.51, session replay and chat-tool wiretapping claims, call recording disputes, and two-party consent litigation. Statutory damages of $5,000 per violation. One of the most active California privacy theories in 2025–2026.
  • California Consumer Privacy Act and CPRA. Data breach claims under the private right of action, deletion and access request disputes, and regulatory matters before the California Privacy Protection Agency.
  • Unfair Competition Law (UCL). Cal. Bus. & Prof. Code § 17200. The most expansive consumer protection statute in the country. Defenses focus on standing, restitution limits, and the absence of a damages remedy.
  • Consumer Legal Remedies Act (CLRA). Cal. Civ. Code § 1750 et seq. Class action exposure for misrepresentation claims, with statutory minimum damages and attorneys' fees that fuel plaintiffs' filings.
  • California TCPA analogues. California state law claims paralleling federal TCPA exposure, often filed alongside federal §227 claims to maximize damages calculations.
  • Ninth Circuit appellate practice. Class certification appeals under Rule 23(f), interlocutory appeals, and merits appeals. The Ninth Circuit's class certification doctrine after Olean Wholesale Grocery v. Bumble Bee Foods is among the most consequential in the country.
The Los Angeles Partners

Two Partners Leading the Los Angeles Practice.

The Los Angeles office is led by partners Nathaniel Haas and Matthew Venezia. Both partners engage directly on the matters they take on, with senior involvement from the first call through resolution.

Partner · LA Office Founder
Nathaniel Haas
USC Gould Lecturer in Law

Nathaniel founded Watstein Terepka’s Los Angeles office. He represents high-profile clients in state and federal courts and arbitrations nationwide, with class action experience spanning consumer fraud, antitrust, landlord-tenant, mass tort, and securities litigation. Before joining WT, he was a partner at Kirkland & Ellis. He clerked for Judge Morgan B. Christen of the U.S. Court of Appeals for the Ninth Circuit and earned his J.D. from USC Gould School of Law, where he now serves as a Lecturer in Law.

Practice focus: consumer fraud class actions · antitrust litigation · landlord-tenant class actions · mass tort · securities defense · Ninth Circuit appeals
Prior firm: Kirkland & Ellis (Partner)
Clerkship: Hon. Morgan B. Christen, U.S. Court of Appeals for the Ninth Circuit
Education: USC Gould School of Law (J.D.); Lecturer in Law (current)

Direct line: (213) 526-1880 Email: NHaas@wtlaw.com Profile: Full bio →
Partner
Matthew Venezia
Two Published Ninth Circuit Opinions

Matthew is a partner in Watstein Terepka’s Los Angeles office. He specializes in class action, intellectual property, false advertising, and anti-discrimination litigation, with two published Ninth Circuit opinions to his name. He obtained class certification and lead counsel appointment in litigation challenging the UNOS race-based kidney function score adjustment. Matthew joined WT from Ellis George LLP and earned his J.D., cum laude, from Washington University School of Law in St. Louis.

Practice focus: class action litigation · intellectual property · false advertising defense · anti-discrimination class actions · Ninth Circuit appellate practice
Notable matter: lead counsel in UNOS race-based kidney function score adjustment litigation (class certified)
Prior firm: Ellis George LLP
Education: Washington University School of Law (J.D., cum laude)

Direct line: (213) 753-1337 Email: MVenezia@wtlaw.com Profile: Full bio →

Firm co-founder Alexander Terepka (Chambers USA-ranked individual) also maintains a Los Angeles presence and partners directly with the LA team on class action and complex commercial matters.

Practice Focus

What the Los Angeles Office Handles

The Los Angeles office is built around the practice areas where California exposure is highest and where Ninth Circuit precedent matters most.

Class Action Defense

Rule 23 certification fights, Ninth Circuit class-cert appeals, and California-specific consumer class actions under the UCL, CLRA, and FAL. Practice page →

TCPA Litigation

Telephone Consumer Protection Act class actions and individual claims. ATDS, prerecorded message, SMS, and revocation disputes filed in California federal courts. Practice page →

CIPA & Privacy Litigation

California Invasion of Privacy Act defense — session replay, pen register theories, call recording. CCPA and CPRA litigation. Practice page →

False Advertising & IP

Lanham Act, UCL, FAL, and CLRA false advertising defense. Trademark and trade dress litigation in California federal courts.

Anti-Discrimination Class Actions

Defense of class actions alleging discrimination in pricing, scoring, eligibility, and algorithmic decision-making — including healthcare and consumer-facing systems.

Ninth Circuit Appellate Practice

Class certification appeals under Rule 23(f), interlocutory appeals, and merits appeals. Practice page →

Track Record

Result Callouts From the Los Angeles Practice

Two Published Ninth Circuit Opinions Partner Matthew Venezia has built Ninth Circuit precedent for defendants in class action and false advertising matters that practitioners across California cite.
Class Certification & Lead Counsel — UNOS Litigation Matthew Venezia obtained class certification and lead counsel appointment in litigation challenging the United Network for Organ Sharing's race-based kidney function score adjustment.
Ninth Circuit Clerkship Founder Nathaniel Haas clerked for Judge Morgan B. Christen of the U.S. Court of Appeals for the Ninth Circuit before partnering at Kirkland & Ellis and founding WT's Los Angeles office.
Common Questions

Common Questions About Watstein Terepka's Los Angeles Office

Watstein Terepka LLP’s Los Angeles office is located at 515 South Flower Street, 19th Floor, Los Angeles, California 90071, in the downtown Los Angeles financial district. The main number for the Los Angeles office is (213) 526-1880.

Watstein Terepka’s Los Angeles office is led by partners Nathaniel Haas and Matthew Venezia. Nathaniel Haas founded the Los Angeles office. He was previously a partner at Kirkland & Ellis and clerked for Judge Morgan B. Christen of the U.S. Court of Appeals for the Ninth Circuit. Matthew Venezia has two published Ninth Circuit opinions and obtained class certification and lead counsel appointment in litigation challenging the UNOS race-based kidney function score adjustment.

The Los Angeles office defends class actions, TCPA litigation, California Invasion of Privacy Act (CIPA) claims, false advertising matters, intellectual property litigation, anti-discrimination class actions, and Ninth Circuit appellate matters. The office represents defendants in California state courts, the Central District of California, the Northern, Eastern, and Southern Districts of California, and the U.S. Court of Appeals for the Ninth Circuit.

Yes. Watstein Terepka’s Los Angeles partners defend California Invasion of Privacy Act (CIPA) claims involving session replay, chat-tool wiretapping allegations, pen register and trap-and-trace theories under Cal. Penal Code § 638.51, and call-recording disputes. CIPA’s two-party consent requirement and statutory damages of $5,000 per violation make CIPA one of the most active California privacy plaintiffs’ theories.

Yes. Watstein Terepka’s Los Angeles office handles Ninth Circuit appellate matters, including class certification appeals under Rule 23(f), interlocutory appeals, and merits appeals in class action, TCPA, privacy, and false advertising cases. Partner Nathaniel Haas clerked for Ninth Circuit Judge Morgan B. Christen. Partner Matthew Venezia has two published Ninth Circuit opinions.

Watstein Terepka’s Los Angeles office can be reached by phone at (213) 526-1880, by email at LAoffice@wtlaw.com, or by mail at 515 South Flower Street, 19th Floor, Los Angeles, CA 90071. Inquiries are routed to a Los Angeles partner.

Yes. In addition to the Los Angeles office, Watstein Terepka LLP has offices in Atlanta, Georgia and Miami, Florida. The firm’s nationwide litigation practice serves clients across all 50 states and in federal courts of appeals throughout the country.

Yes. Watstein Terepka defends California Consumer Privacy Act (CCPA) and California Privacy Rights Act (CPRA) litigation from its Los Angeles office, including data breach claims under the private right of action, deletion and access request disputes, and regulatory matters before the California Privacy Protection Agency.

Engage LA Counsel

Facing a California class action, CIPA claim, or Ninth Circuit appeal?

Inquiries to the Los Angeles office are routed to a partner. Reach the LA office at (213) 526-1880 or LAoffice@wtlaw.com.

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