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.
Genuinely curious, when is this the case? If you’re programming on your own then it just takes the option of controlling what others do to your work off the table for no benefit - if you go copyleft and someone uses it and you don’t “mind” them using it then you can give/sell them an exemption while retaining the ability to go after uses that you don’t like.
I’ve been in situations where I wanted to retain credit/ownership of ideas and code, but wanted to be able to use them in the workplace. So building a MIT/BSD licensed library on the weekend and then importing it on Monday was the only game in town. I get the portfolio piece and my job is easier as a result. But I stick to non-novel and non-patentable stuff - “small” work really, as Stallman is quoted here..
In some work environments, GPL or “GPL with an exception” would never get the kind of traction it should. Lots of places I’ve worked lack the legal and logistical framework for wrangling licenses and exceptions. It’s hard to handle such cases if there’s literally nobody to talk to about it, while you have automated systems that flag GPL license landmines anyway. The framing is a kind of security problem, not a license problem, so you never really get to start.