That's the change here. Historically the GPL distribution language was a condition of the copyright license, so exactly as you said, no one could sue you because there was no separate contract element to end users binding them into a contract with anyone.
That is what is so exciting / different about this. When you make available software under the GPL, you have now entered into a CONTRACT (not copyright anymore) with all users that binds you to the terms of the GPL and gives them a right to sue for violations of THEIR independent rights.
This is the power of this new ruling, they can then sue you or anyone for breaking this agreement with them. Obviously will take some experience to see how far this can be taken. My understanding is the conservancy may want to try to leverage this to try to get GPLv3 effects into GPLv2 and a few other things the developers of for example Linux are not so hot on.
> When you make available software under the GPL, you have now entered into a CONTRACT (not copyright anymore) with all users that binds you to the terms of the GPL and gives them a right to sue for violations of THEIR independent rights.
Sure, anyone can sue you for anything. However nothing in this removes the copyright holders' ability to issue non-GPL licenses. A user of a product that uses a non-GPL license for that code would still have no standing for that suit.
Historically one could contribute to a GPL project (potentially on a significant level for a corp) but wouldn't worry too much about using it in your own product that was potentially locked down - ie, DRM / motor duty cycle control, rev limits etc.
Linus / Linux have a long history of being pretty relaxed about your use cases, with the one key provision that you share your code.
Now, the group of people who can sue you is much larger. And some of them (conservancy in particular) may have views that don't align with your GPLv2 interpretation (particularly around tivoization / lock down issues for hardware devices). So if you are contributing too and shipping GPLv2 code - yes, you as the distributor of a larger body of code probably have a higher risk now of being sued.
Some links on the topic of GPLv2, installation, tivo and GPLv3. The Conservancy position seems to be that GPLv2 requires allowing installation but that what Tivo did (breaking proprietary software when you modify GPL software) is allowed by both GPLv2 and GPLv3. The main reason the GPL exists is to give downstream users the right to run modified versions, so their interpretation of GPLv2 seems reasonable to me.
The main reason the GPL exists was to insure changes to code (forks) were available to original developers of the code so they could include those changes if they wanted (this was a result of issues with earlier unix systems that had fragmentation from forks). Additional, Linus, author of Linux, has been clear that his focus is getting code back, what happens to hardware was not covered in his mind by GPLv2.
So there is a dispute as to what GPLv2 requires with respect to hardware. It's clear that the code must be shared, and that's what a lot of GPLv2 devs have focused on. That the source code be shared, including scripts used for compilation and installation.
But (one view) is that is separate from mandating behavior of hardware, and that hardware can still check if its running approved code and refuse to run if approved code is not loaded.
That's why this case is so huge. The actual developers of Linux are not likely to try to enforce a term they don't think exists, the SFC very well may.
Nothing in the GPL requires giving back, only giving forward to downstream users, who may or may not give back or even publish what they received.
So what Linus wants from the GPL isn't even mentioned in the GPL.
It is only through a culture of contributing upstream and through upstreams reaching out to downstream redistributors and asking them to contribute upstream that anything gets upstream at all.
I suggest you read Conservancy's posts and the GPL, it does mention that installation is required to be possible and this requirement has always been present and enforced by copyright holders for GPL software, including for Linux itself.
That is what is so exciting / different about this. When you make available software under the GPL, you have now entered into a CONTRACT (not copyright anymore) with all users that binds you to the terms of the GPL and gives them a right to sue for violations of THEIR independent rights.
This is the power of this new ruling, they can then sue you or anyone for breaking this agreement with them. Obviously will take some experience to see how far this can be taken. My understanding is the conservancy may want to try to leverage this to try to get GPLv3 effects into GPLv2 and a few other things the developers of for example Linux are not so hot on.