The Use of Technical Experts in Software Copyright Cases: Rectifying the Ninth Circuit’s 'Nutty' Rule

45 Pages Posted: 15 Jul 2020 Last revised: 6 Oct 2020

See all articles by Shyamkrishna Balganesh

Shyamkrishna Balganesh

Columbia University - Law School

Peter S. Menell

University of California, Berkeley - School of Law

Date Written: June 21, 2020


Courts have long been skeptical about the use of expert witnesses in copyright cases. More than four decades ago, and before Congress extended copyright law to protect computer software, the Ninth Circuit in Krofft Television Prods., Inc. v. McDonald’s Corp., ruled that expert testimony was inadmissible to determine whether Mayor McCheese and the merry band of McDonaldland characters infringed copyright protection for Wilhelmina W. Witchiepoo and the other imaginative H.R. Pufnstuf costumed characters. Since the emergence of software copyright infringement cases in the 1980s, substantially all software copyright cases have permitted expert witnesses to aid juries in understanding software code. As the Second Circuit recognized in Computer Associates Int’l, Inc. v. Altai, Inc., the ordinary observer standard may well have served its purpose when the material under scrutiny was limited to art forms readily comprehensible and generally familiar to the average lay person,” but as to computer programs, district courts must have “discretion . . . to decide to what extent, if any, expert opinion, regarding the highly technical nature of computer programs, is warranted in a given case.”

In a shocking departure from the decisions of every other circuit that has confronted software copyright infringement litigation, the Ninth Circuit reaffirmed and applied the bar on expert testimony originating in Krofft Television Prods. to all copyright disputes, including those involving highly technical computer software code. The court in Antonick v. Electronic Arts held that lay juries must decipher and analyze software code—distinct hexadecimal assembly code languages for different processors—without the assistance of expert witnesses, a rule that the authoring judge characterized at the oral argument as “nutty.”

The Ninth Circuit’s rule overlooks the key distinction between the use of technical experts to analyze substantial similarity as opposed to enabling lay judges and jurors to perceive the underlying works. Just as it would be absurd to ask a lay jury with no familiarity with Kanji characters to assess whether a translation of HARRY POTTER AND THE PHILOSOPHER’S STONE into Japanese infringed the English original without the aid of a bilingual translator, it makes no sense to ask a non-technical jury to compare computer source codes written in different assembly languages to determine substantial similarity without expert assistance. We contend, consistent with the views of every court outside of the Ninth Circuit that has addressed the issue, that courts should permit the use of technical experts to enable lay judges and juries to perceive the meaning of computer languages and computer code.

Keywords: copyright, software, computer software, expert witness

Suggested Citation

Balganesh, Shyamkrishna and Menell, Peter S., The Use of Technical Experts in Software Copyright Cases: Rectifying the Ninth Circuit’s 'Nutty' Rule (June 21, 2020). Berkeley Technology Law Journal, Vol. 35, 2021, U of Penn Law School, Public Law Research Paper No. 20-39, Available at SSRN:

Shyamkrishna Balganesh

Columbia University - Law School ( email )

435 West 116th Street
New York, NY 10025
United States


Peter S. Menell (Contact Author)

University of California, Berkeley - School of Law ( email )

215 Boalt Hall
Berkeley, CA 94720-7200
United States

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