Once upon a time in the 2000s and 2010s, Patrick McHardy was the chair of Linux's Netfilter core development team. Netfilter is a Linux kernel utility that handles various network functions, such as facilitating Network Address Translation (NAT) and Linux's IPTables firewall. All was fine. But, then it was discovered that McHardy had made millions of Euros from threatening over 50 companies with legal action for using "his" code. That will never happen again.
McHardy was suspended from the Netfilter team in 2016. The Netfilter team released a document on how to deal with his attempts to extract money from vendors. This move by McHardy, who had been a leading Linux developer in the 2000s, came as a complete surprise at the time. Now, years later, the issue has finally been resolved.
On January 24, 2022, the Netfilter project announced a legally binding settlement with McHardy. This settlement has been ratified in a German court decision. This settlement governs any legal enforcement activities concerning all programs and program libraries published by the Netfilter/IPTables project and the Linux kernel.
Earlier, in 2018 McHardy gave up on his Gnu General Public License version 2 (GPLv2) violation case against Geniatech Europe GmbH. That was the end, as far as is known, of McHardy's attempts to monetize the open-source code.
Still, the issue was still there. So, in the current agreement, the active Netfiler programmers and McHardy mutually agreed not to enforce in the future the infringement of their copyrights (including copyrights in joint authorship and/or adaptations) in the software and/or the infringement of GPL in connection with the code without the prior consent of the majority of the then active Netfilter Core Team members.
McHardy is not a member of the Netfilter Core Team. Nor, does it even seem possible he'll ever be a member again.
This should end the conflict once and for all.
Looking ahead, the Netfilter project continues to endorse "The Principles of Community-Oriented GPL Enforcement. " The most important phrase within it is that open-source license enforcement "must never prioritize financial gain." Of course, this settlement does not release third parties from their obligations to comply with the GPL.
It was never the intention of Linux developers to make money from GPL enforcement. As Greg Kroah-Hartman, Linux kernel maintainer for the stable branch said in In October 2017 "McHardy has sought to enforce his copyright claims in secret and for large sums of money by threatening or engaging in litigation. Some of his compliance claims are issues that should and could easily be resolved. However, he has also made claims based on ambiguities in the GPL-2.0 that no one in our community has ever considered part of compliance."
Kroah-Hartman continued, "We have never even considered enforcement for the purpose of extracting monetary gain. It is not possible to know an exact figure due to the secrecy of Patrick's actions, but we are aware of activity that has resulted in payments of at least a few million Euros. We are also aware that these actions, which have continued for at least four years, have threatened the confidence in our ecosystem."
This final agreement is meant to underline that the Linux community has never intended to use the GPL to extort money from users.