On October 19, 2021, the Software Freedom Conservancy (SFC) sued Vizio, Inc. for alleged violations of the GNU General Public License covering software embedded in certain Vizio smart TVs.
The use of open source software has become increasingly popular in the development of proprietary commercial software, including software embedded in hardware devices such as consumer electronics. Open source software can provide important and useful functionality and is increasingly used by developers to reduce development time.
The licensing models under which open source software is made available can be classified into two broad categories: permissive licenses and copyleft licenses. Permissive open source licenses generally do not create significant barriers to the incorporation of open source software into proprietary commercial software products. Copyleft licenses, however, can be extremely problematic for developers of proprietary software and hardware. The terms of such licenses may require that, if any software that incorporates or interacts with open source software and is distributed, the distribution of such modified software is governed by the same copyleft license. For this reason, some people refer to these types of open source licenses as “viral”. This term is intended to refer to the effect of licenses of capturing (some use the term “infect”) an ever increasing amount of software code.
The requirement for copyleft licenses that tends to be the most inconsistent with the proprietary software model is the requirement that the source code of the modified software be made available to the public.
One of the most commonly used copyleft licenses is the GNU General Public License, in all its versions: GPLv2, GPLv3, LGPLv2.1, AGPL, etc. The language of the GPL is notoriously vague, which can make it difficult to determine when a software product is sufficiently connected to open source software to fall under the copyleft regime. A number of popular open source projects are licensed under copyleft, such as the Linux kernel and many related programs, the source code of which is released under GPLv2 and LGPLv2.1.
In its complaint, the SFC alleges that Vizio included the Linux kernel and several associated open source programs in its SmartCast system for smart TVs. SFC further alleges that the sale of these Vizio smart TVs constitutes a distribution of the software under the GPL license and that Vizio is therefore in breach of its obligations under the GPL license. Specifically, SFC claims that the SmartCast system is covered under the terms of the GPL, and therefore the source code for the SmartCast system is to be made available by Vizio.
The SFC has presented this litigation as the defense of consumer rights, including the rights to repair products and accelerate the development of product improvements that incorporate open source software licensed by copyleft.
The SFC alleges that, starting in August 2018, the SFC repeatedly requested Vizio to provide the source code for its SmartCast system in accordance with its obligations under the GPL license. Versions of the source code for SmartCast were provided by Vizio at various times after August 2018, but in each case the SFC alleges that its representatives were unable to compile the source code provided by Vizio.
The California court and jury will have to decide a number of interesting questions in this case, including the level of source code disclosure required to comply with the GPL.
Although copyleft license disputes are rare, there have been several previous cases. In 2008, legal action was initiated by the Free Software Foundation (FSF) against Cisco Systems (Free Software Foundation, Inc. v Cisco Systems, Inc). The FSF alleged that several of Cisco’s consumer network routers used GPL-licensed code. The dispute was settled and Cisco released the source code, provided input to the FSF, and appointed a compliance officer.
There have also been several open source licensing cases in dispute in Germany. In a first case Welte v. Sitecom, a Welte complainant (developer of open source networking software released under the GPL) alleged that a German subsidiary of Sitecom used its GPL-licensed code in one of its wireless products without meeting its obligations under the GPL. The German court ruled that the Sitecom subsidiary was required to provide a notice of the license, including the text of the GPL license, and was required to distribute its code under the same license. The case also resulted in an injunction against Sitecom.
Welte won another case in Germany, Welte vs. D-Link, in which it alleged that D-Link (a Taiwanese manufacturer of networking solutions) distributed a network storage device that used a Linux-based operating system. On September 6, 2006, the German District Court handed down its judgment in Welte’s favor.
The Vizio trial is just the most recent reminder of the importance of understanding the requirements and risks associated with the use of open source software, and in particular, its integration into proprietary commercial products. While open source software can be a powerful tool in the development of agile software, it is essential that proprietary software developers create strong strategies and policies to understand and comply with applicable open source licenses. Many software developers still take open source licenses for granted and believe that the code can be used without obligation. This lawsuit against Vizio is the latest reminder that the risks are not theoretical.