Karl Kronenberger

415-955-1155 , Ext. 114
[email protected]
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Karl Kronenberger is an indispensable resource and trusted advisor to his clients on issues relating to Internet law, media, and technology.

A seasoned litigator, Karl has tried more than 20 jury trials and many more bench trials, and he regularly handles complex Internet law issues, such as Internet trademark and copyright infringement, spam litigation defense, Internet defamation and false advertising, cybersquatting, FTC lawsuits, data breaches, website agreements, and privacy disputes. Karl thrives on litigating matters where the legal terrain is uncharted, as is often the case in the realm of Internet disputes.

As a former general counsel to technology and non-technology companies alike, he has handled many of the day-to-day legal issues these companies face, including intellectual property issues, licensing and distribution agreements, and domain name disputes. Additionally, he handles a variety of transactions and business disputes for services, technology, and media companies.

A former prosecutor and Army JAG Corps officer, he is both aggressive and creative in solving problems, while maintaining the highest of ethical standards.

“Representing clients zealously, maintaining the highest ethical standards, and communicating well with clients are the foundations of my practice.”

Karl is frequently called upon as an Internet law expert by the media and at industry conferences. He has received the highest “AV Preeminent” rating by his peers through Martindale-Hubbell and is named to the 2011 list of Northern California Super Lawyers for his work in Internet law.

Karl has appeared as an expert witness in both federal and state courts on a variety of topics, including practices and procedures in litigating spam cases in California; standards and practices of the Federal Trade Commission concerning enforcement of advertising laws; Amazon policies regarding intellectual property infringement and other prohibited activities; and counterfeiting and other trademark infringement within the Amazon Marketplace.

Karl is licensed to practice in California, New York, Georgia, and Ohio and before the District Courts for the Northern, Central, and Southern Districts of California, District Court for the Southern District of New York, District Court for the Northern District of Georgia, District Court for the Southern District of Ohio, and the United States Court of Appeals for the Ninth Circuit. He is a member of the American Bar Association and the Bar Association of San Francisco.

He is a graduate of the University of Notre Dame (1990) and the University of Cincinnati College of Law (1993).

  • Represented a major Internet advertising network in $11 million federal spam lawsuit by professional spam plaintiff. Prevailed on behalf of the client at summary judgment on all claims in the lawsuit. Obtained order awarding over $806,000 in fees and sanctions against the professional spam plaintiff, which pushed plaintiff into insolvency and caused them to cease operations.
  • Represented a cloud computing and file sharing company backed by more than $600 million in venture financing in a lawsuit where the firm successfully obtained the domain name containing the client’s primary trademark.
  • Represented a social networking app developer backed by more than $350 million in venture financing in a TCPA class action lawsuit. Obtained speedy settlement and voluntary dismissal of putative TCPA class action against client, after early discovery and independent research by the Firm demonstrated that the SMS text message at issue was initiated by the plaintiff’s acquaintance, not the client.
  • Represented a medical records imaging technology company in lawsuit against an unknown person who hacked into client’s network. Upon discovering that the hacker was a competitor, and that the competitor stole trade secrets and used them to compete with client, the Firm amended the John Doe complaint to name the competitor as a defendant, leading to a complete win in the case and the criminal indictment of the defendant competitor.
  • Represented an international nonprofit organization in lawsuit involving theft of its trade secrets and dissemination of such trade secrets by defendants anonymously via multiple blogs.
  • Seized a domain name portfolio from a notorious cybersquatter and judgment debtor, auctioned the domain name portfolio for $302,000, and in the process created new Ninth Circuit law concerning the ability to seize domain names as property.
  • Represented defendants in an FTC lawsuit alleging $350 million in damages arising from what the FTC described as “bogus free trial offers,” including preparing and presenting nine expert witnesses in an opposition to a preliminary injunction.
  • Represented defendants in a FTC lawsuit involving $42.5 million regarding unsolicited SMS text messages marketing free gift cards, resulting in a public settlement where defendants paid only a fraction of the damages alleged by the FTC.
  • Represented a medical school in lawsuit against a bogus non-profit consumer review website and company; following a round of subpoenas served on various service providers for defendants, the firm discovered that the defendant was actually controlled by a direct competitor of the client. The matter settled promptly after this revelation.
  • Represented the nation’s largest broker of moving and relocation services in false advertising lawsuit against a so-called consumer review website. The complaint alleged that defendant engaged in search engine spam by numerous uses of our client’s trademark under the auspices of a “black list,” which directly benefited the competitors of the firm’s client.
  • Represented defendants in a trade secrets lawsuit brought by their former employer, a reseller of computer hardware and software.  The defendants left the employ of the plaintiff and proceeded to compete directly with plaintiff, including with plaintiff's customers.  The plaintiff alleged that defendants used trade secret information in soliciting the exact customers with which defendants worked while employed by plaintiff.  After a 30-day jury trial, the jury returned a unanimous verdict that the defendants did not misappropriate any trade secrets of the plaintiff.
  • Represented the nation’s top retailer of ink and toner products in a false advertising lawsuit brought by a billion dollar printer manufacturer.
  • Represented the U.S. Chess Federation in a lawsuit involving unknown parties hacking into the email account of a member of the board of directors of our client, and stealing information regarding the internal investigation of two other directors of the organization (Susan Polgar and Paul Truong). After multiple rounds of subpoenas, the firm discovered that the person responsible for the hacking was an employee of Susan Polgar, which led to the criminal indictment of such employee and an eventual resolution of the case.
  • Defeated motion for class certification in hotly-contested, multi-million dollar consumer class action against Internet advertiser by using arguments made by plaintiff in refusing to arbitrate—namely, that the version of the website plaintiff viewed did not contain certain disclosures—against him to demonstrate that plaintiff could not establish the requisite commonality or typicality. The case was resolved shortly thereafter through voluntary dismissal by plaintiff and no payment by the client.
  • "Trends in Dealing with Unauthorized Sellers on Amazon," Internet Law Leadership Summit, May 2018
  • "Unpacking Hassell v. Bird," Intellectual Property Law Section of The State Bar of California, April 2017
  • "Legal Issues for Amazon Sellers," Catalyst88, 2017
  • "Copyrightability Under the Copyright Act," Internet Law Leadership Summit, 2016
  • "Online Marketing:  Current Trends & Common Pitfalls," The Intellectual Property and Internet Law Section of the Barristers Club, Bar Association of San Francisco, 2015
  • "Employers' Use of Social Media – NLRB and Other Updates," Internet Law Leadership Summit, 2015
  • "Online Advertising Panel," Bar Association of San Francisco, 2015
  • “The Last Year in Privacy and Security Litigation,” PLI's Sixteenth Annual Institute on Privacy and Data Security Law, 2015
  • “Testimony Regarding AB 2643 Revenge Porn Civil Claim for Relief,” Hearing of Judiciary Committee of California Assembly, 2014
  • “New TCPA Requirements and Surging SMS Spam Litigation,” State Bar of California, Business Law Section, Cyberspace Committee, 2013
  • “Recent Developments in TCPA Compliance and Litigation Regarding SMS Spam,” State Bar of California, Business Law Section, Cyberspace Committee, 2013
  • “Serving Subpoenas on ISPs, Email Providers and other Vendors: Pitfalls and Best Practices,” Internet Law Leadership Summit, 2013
  • “Spam Litigation Update,” Internet Law Leadership Summit, 2013
  • “SMS Spam Litigation Explosion,” Internet Law Leadership Summit, 2013
  • “Spam Law Thunderdome: A Vigorous Debate on Current Spam Law Developments,” Internet Law Leadership Summit, 2013
  • “Mobile Privacy & COPPA: Recent Updates and Impending Regulatory Changes,” Internet Law Leadership Summit, 2013
  • “Mobile Privacy and SMS Marketing: Recent Updates and Impending Regulatory Changes ‘Hot Topic’ Presentation,” Business Law Section of the State Bar of California, 2013
  • “Enforcing IP on the Internet: Ethical Issues and Investigative Tools in Pursuing Anonymous Infringers,” 3rd Annual Intellectual Property Law Symposium, 2012
  • “Waging War on Anonymous Bad Actors on the Internet,” ABA Winter Working Meeting and Cyberspace Law Institute, 2012
  • Should Companies Pay Data Hacking Ransoms? (Interview with Karl Kronenberger), Lawyer Monthly, July 2016
  • The Other Way Around: American Entrepreneurs Buy Chinese Goods to Sell - But Lose Out on Patent Protection, Corporate Counsel, May 2016
  • Diet Pill Companies Settle FTC Advertisement Claims, Daily Journal, February 2016
  • Giant Slayers:  The Small, Hyper-Focused Firms That Take on Big Matters and Win, Daily Journal, October 2015
  • Waze Ripped Off Rival's Data, Suit Alleges, The Recorder, September 2015
  • Google, Waze Hit with Copyright Suit Over Rival Traffic Data, Law360, September 2015
  • I Was Paid to Write this Blog, Direct Marketing News, August 2015
  • FTC's Social Media Promotion Guide Has Marketers Confused, Law360, July 2015
  • Firms Aim to Track Clients on Websites, Daily Journal, July 2015
  • Fired Workers Increasingly Add Defamation Claims to Their Lawsuits, ABA Journal, May 2015
  • Cybersquatters’ wreak havoc with '16 field, The Hill, May 2015
  • From TedCruz.ca to TaylorSwift.porn: How the Golden Age of Domain-Trolling Was Born, Washington Post, March 2015
  • More Law Firms To Face Suits Over Sensitive Client Data, Law360, March 2015
  • Tech Titans, Daily Journal, February 2015
  • Can employees comment about their employer on social media sites?, Inside Counsel, February 2015
  • Paris mayor may sue Fox News over no-go-zones report, USAToday, January 2015
  • NetJets pilot union sues for violations of labor and privacy laws, Inside Counsel, December 2014
  • Customer lists ‘in the heads’ of ex-employees, Intellectual Property Magazine, December 2014
  • Pilots Union Sues NetJets over Twitter Account, Flying Magazine, December 2014
  • San Jose Jury Returns Groundbreaking Revenge Porn Verdict, The Recorder, February 2014
  • Legal recourses limited for Te’o to seek, USA Today, January 2013
  • Not So Fast, Keith Olbermann, New York Magazine, July 2010
  • Government Filing Connects Polgar to Criminal Case, New York Times, July 2010
  • Politicians Face Consequences If They Don’t Secure Name Domains, PBS, May 2010
  • Online Libel Claims Abound, California Lawyer, June 2009
  • Appeared as Expert on Internet Defamation, Countdown with Keith Olbermann, 2008
  • Appeared as Expert on Net Neutrality, ABC News NOW, 2008


  • How to Comply with FTC Guidelines for Social Media Campaigns, Daily Journal, April 2017
  • Business Of All Sizes Should Keep Website Terms Up to Date, Daily Journal, January 2017
  • Winning the Fight Against Email Spam Plaintiffs, Intellectual Property and Technology Law Journal, October 2016, Vol. 28, No. 10
  • Defending Against Spam Shakedowns, Daily Journal, June 2016
  • Endorsements, Reviews, and Astroturfing: New FTC Guidance for Marketers, MarketingProfs, January 2016
  • New FTC Requirements for Affiliate Marketers, FeedFront, Issue 32, October 2015
  • Customer Lists "in the heads" of Ex-Employees, Intellectual Property Magazine, 2015
  • The Tension Between Principles of “Sunshine Laws” and “The Right to be Forgotten” – Trends in the Treatment of Personal Information on the Internet, Inside the Minds: Understanding Developments in Cyberspace Law, 2014 ed., 2014
  • Fight Back Against Internet Defamation (a war story from a battle-hardened attorney), Directions, IMA Newsletter, 2009
  • Defamation Superhighway, Daily Journal, 2009
  • University of Notre Dame, B.A., Government with PPE Concentration (Philosophy, Politics, Economics)
  • University of Cincinnati College of Law, J.D.
  • State Bar of California
  • State Bar of New York
  • State Bar of Georgia
  • State Bar of Ohio
  • U.S. District Court for the Northern District of California
  • U.S. District Court for the Central District of California
  • U.S. District Court for the Eastern District of California
  • U.S. District Court for the Southern District of California
  • U.S. District Court for the Southern District of Ohio
  • U.S. District Court for the Southern District of New York
  • U.S. District Court for the Northern District of Georgia
  • U.S. District Court for the Northern District of Florida
  • U.S. District Court for the Western District of Wisconsin
  • U.S. District Court for the Eastern District of Michigan
  • U.S. District Court for the District of Colorado
  • U.S. District Court for the Western District of Texas
  • The United States Court of Appeals for the Ninth Circuit
  • The United States Court of Appeals for the Tenth Circuit
  • American Bar Association
  • Cyberspace Committee of the Business Law Section of the California State Bar (Co-Chair, 2014-2015)

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