William Zac

Duffy

Shareholder
500 N. Akard Street, Suite 4000
Dallas, TX 75201-6605

Overview

Zac focuses his practice on intellectual property and technology law. He received his undergraduate degree in Management Information Systems (MIS) at the University of Oklahoma and spent several years working as a technical resource at a software company that served banks and other financial institutions. Zac’s background allows him to provide valuable counsel on matters that involve some form of technology, including software copyright infringement, patent litigation and complex trade secret cases.

Software: Zac assists clients with software contracts, including software as a service (SaaS) agreements and contracts to develop or host new software applications for third parties. He has also represented parties in litigation over unpaid service fees and disputes about software deliverables.

Trademarks: Zac represents companies in trademark litigation over alleged violations of the Lanham Act and related claims for unfair competition and false advertising. He has filed a large number of trademark applications with the United States Patent and Trademark Office (USPTO) and has also represented clients in trademark opposition proceedings brought before the Trademark Trial and Appeal Board (TTAB).

Patent Litigation: Many of Zac’s clients are companies involved in patent litigation over a wide variety of technologies, including digital video security systems, Radio Frequency Identification (RFID), medical devices, oil and gas tools and systems, and consumer electronics.

Data Privacy/Cybersecurity: Zac provides counsel on data privacy and cyber security law, including updating Privacy Policies and related practices to comply with US federal and state laws and the EU GDPR. He has also assisted companies in responding to data breach incidents, and has represented clients involved in regulatory actions by the FTC for alleged violations of data privacy laws and regulations.

Education

Admissions

Achievements

  • Thomson Reuters – Texas Rising Stars (2011-2018)
  • Woodward/White, Inc. – Best Lawyers in America, Litigation – Intellectual Property (2025)

Overview

Zac focuses his practice on intellectual property and technology law. He received his undergraduate degree in Management Information Systems (MIS) at the University of Oklahoma and spent several years working as a technical resource at a software company that served banks and other financial institutions. Zac’s background allows him to provide valuable counsel on matters that involve some form of technology, including software copyright infringement, patent litigation and complex trade secret cases.

Software: Zac assists clients with software contracts, including software as a service (SaaS) agreements and contracts to develop or host new software applications for third parties. He has also represented parties in litigation over unpaid service fees and disputes about software deliverables.

Trademarks: Zac represents companies in trademark litigation over alleged violations of the Lanham Act and related claims for unfair competition and false advertising. He has filed a large number of trademark applications with the United States Patent and Trademark Office (USPTO) and has also represented clients in trademark opposition proceedings brought before the Trademark Trial and Appeal Board (TTAB).

Patent Litigation: Many of Zac’s clients are companies involved in patent litigation over a wide variety of technologies, including digital video security systems, Radio Frequency Identification (RFID), medical devices, oil and gas tools and systems, and consumer electronics.

Data Privacy/Cybersecurity: Zac provides counsel on data privacy and cyber security law, including updating Privacy Policies and related practices to comply with US federal and state laws and the EU GDPR. He has also assisted companies in responding to data breach incidents, and has represented clients involved in regulatory actions by the FTC for alleged violations of data privacy laws and regulations.

Experience

  • Copyright, Patent + Trademarks

    Represented Seasons USA, a leading manufacturer of novelty holiday-related toys, costumes and decorations, in a series of copyright, patent and trademark

    [more]
  • Trademarks (Trademark Trial and Appeals Board)

    Represented a software services company in trademark opposition proceeding.

  • Software

    Represented a software development company in litigation over unpaid fees allegedly due to faulty or defective software deliverables.

[more]