Protect Your Open-Source Project Before It's Too Late: A Legal Horror Story
Running a successful open-source project is one of the most rewarding experiences for a developer community. It’s also a journey full of unexpected challenges - some technical, some human, and, as we’ve recently learned, some legal.
This post is both an update on the status of the ExpressLRS project and a cautionary tale for other maintainers of widely adopted open-source software and hardware: if your project becomes popular, you must take legal steps early to protect its name and identity.
What Happened
Imagine spending years building an open-source project, only to find someone else trying to claim its name. On August 25th, 2025, we were notified that an individual, Christopher Henry Sauer (also known as “Christina Sauer”, “Chris Sauer” and by the handles radiomistress, radio-mistress, radio.mistress) had applied to register ExpressLRS as a trademark in China (Application No. 84786671 - screenshot 1, screenshot 2).
On September 8th, 2025, we received further notification of another application from the same individual to register ExpressLRS as a trademark in the United States (Serial No. 99380841).