Copyright in Europe fundamentally does not work like Copyright in US. More precisely, the law does not govern the monetary gains possible from copying but rather the author's artistical expression in the work. Which is kind of moot regarding source code, but, it makes for an important decision: author's rights are created automatically and you cannot transfer them under any circumstances whatsoever.
Per default, the law states that the author retains all rights. They can license it, e.g. to their employer, exclusively; The employer can then sublicense that. However what licenses are possible is exhaustively defined in the law; on an abstract basis at least (e.g. using, creating derivative works, ...). It has been not exactly clear if conditions evoked on a license still have their roots in these licensable acts, or if they are based on contract law - where literally anything goes as long as it's not against the law or immoral.
Both can be enforced. However, I'd argue that it is good that it was decided that this is a copyright law matter, because this gives authors _much_ more protection than contract law, where all circumstances need to be evaluated for each single case and rulings might as well contradict each other.
> However, I'd argue that it is good that it was decided that this is a copyright law matter, because this gives authors _much_ more protection than contract law
Copyright law may give the authors more power; but unfortunately, experience teaches us that there's usually not much incentive for the authors to enforce their rights. (The case in TFA is an exception, since the author profits directly from dual-licensing.).
For this reason, the SFC has been trying to get the courts to also see it as a contract; and specifically, one in which all other possible users of the software are beneficiaries. This gives random third-parties standing to sue for damages. If it works, it means that the SFC (for example) could go around suing companies which violate the GPL without needing involvement from the original copyright holders.
I'm not entirely sure if this is even possible the way copyright in the EU works today. Be that as it may, at least from my perspective what really prohibits me from actually enforcing GPL on my software is funding. I rarely go beyond sending a stern letter, because anything more would be financial suicide in most cases; I might win but it is incredibly hard to prove damages. Punitive damages don't really exist in the EU (or, to be more precise, in the roman-german law system), at least not to the exterme seen in common law systems.
At least in my case, I'd fight tooth and nail for my software, if I don't have to bear the financial risk.
I was simplyfying. What I described is unified in the European Union; however, the outlined distinction is common across the roman-germanic law system whereas the US copyright interpretation is rooted in common law. In Europe, the only countries using common law are UK and Ireland. And while Ireland has mostly unified their copyright law with the rest of the european union, you still see some roots in common law. For example, it is possible that an irish company (a legal person) can become an author of a work, which is impossible under e.g. german law.
And yes: in a common law system, copyright governs literally "the right to copy", which is transferable. In other law systems (which is the distinction I made) the law governs the property rights of the author's expression, which is non-transferrable, you can only license the rights you have.
Per default, the law states that the author retains all rights. They can license it, e.g. to their employer, exclusively; The employer can then sublicense that. However what licenses are possible is exhaustively defined in the law; on an abstract basis at least (e.g. using, creating derivative works, ...). It has been not exactly clear if conditions evoked on a license still have their roots in these licensable acts, or if they are based on contract law - where literally anything goes as long as it's not against the law or immoral.
Both can be enforced. However, I'd argue that it is good that it was decided that this is a copyright law matter, because this gives authors _much_ more protection than contract law, where all circumstances need to be evaluated for each single case and rulings might as well contradict each other.
Not a lawyer yet, though.