Context:
Permissive licenses (commonly referred to as “cuck licenses”) like the MIT license allow others to modify your software and release it under an unfree license. Copyleft licenses (like the Gnu General Public License) mandate that all derivative works remain free.
Andrew Tanenbaum developed MINIX, a modular operating system kernel. Intel went ahead and used it to build Management Engine, arguably one of the most widespread and invasive pieces of malware in the world, without even as much as telling him. There’s nothing Tanenbaum could do, since the MIT license allows this.
Erik Andersen is one of the developers of Busybox, a minimal implementation of that’s suited for embedded systems. Many companies tried to steal his code and distribute it with their unfree products, but since it’s protected under the GPL, Busybox developers were able to sue them and gain some money in the process.
Interestingly enough, Tanenbaum doesn’t seem to mind what intel did. But there are some examples out there of people regretting releasing their work under a permissive license.
That’s actually an important factor for ancient software whose source code was lost. A developer could, for example, declare all their old Atari 2600 games to be under GPL by just announcing it in their news blog. Collectors could then hunt for the binary files and decompile them. Decompiled software is still a derivative work, so that source code would still be under GPL. Sadly I’m just aware of one case from years ago where I can’t even remember the specifics who and which software it was but he was like “I found some floppy disks from the 1980s, I lost the source code but binaries under GPL, so have fun”.