This isn't an open question.
If you don't have a license from the copyright holder, you can't legally use it, except for fair use exemptions: perhaps you could write a blog post criticizing it.
If you don't have a license from the copyright holder, you can't legally use it, except for fair use exemptions: perhaps you could write a blog post criticizing it.
What about public domain works for example? Or you had a good faith belief you had permission from the copyright holder, eg someone misrepresented themselves as the copyright holder, or the copyright holder published the code in public without a copyright notice?
Buying a Rolex from some guy in a car park is different to buying one from a jewelers. The former wouldn't protect you in any way, the later would let you demonstrate a good faith belief that it wasn't stolen, and wasn't fake.
More generally, say if wanted consumer protections consistent with it being a Rolex, or if you wanted to sell it as a Rolex. Then whether you bought it as a fake does matter.
Good faith: that may affect the amount of damages the copyright holder can extract, but it's still illegal to use the software.
Copyright notices: haven't been required for 30 years.
My underlying point though was that it was an unreasonable answer, to just copy paste the previous answer. No one here that I've seen has claimed to be a lawyer, and no one I've seen has defined what nations laws we are talking about. At that level of discourse, the question posed, deserved a reasonable answer.
Nope, only on works published over 30 years ago. This package was published only three years ago, regardless of when it was created.
There really isn't much nuance under the copyright rules almost universally agreed under treaties like Berne, UCC and TRIPS. This kind of what-ifing a clear statement just sounds like a bad movie trope.
And if you get enough money and lawyers in one place you can create plenty of nuance.
Dragonwriter reminded me of the term, implied licence in another subthread. That clearly seems arguable in this case even if it isn't considered winnable. Case law progresses through winning 'unwinnable' cases.
I think we're approaching this from completely different positions though. I appreciate the what-ifing, exploring the hypotheticals. It isn't as if we have any power to make a difference in a court of law, and I would hope no one is relying on this thread for legal advice.
If Coca Cola writes down its proprietary recipe on their entrance "by mistake", I can definitely make use of it. Maybe I can't photocopy it for sale, but I can definitely re-use their previously-secret techniques.
I can even say I got it from them through their own error and have the exact same outputs for the exact same inputs.
Trade secrets aren't your secret anymore once you publish them.
All we know in this case is that copyright law was used as a tool to remove it.
Courts strongly disagree with you.
If you reverse engineer a system and write a spec using clean-room technique, it's going to be massively easier for the team to do it if they have lawful access to the no-longer proprietary source code.
And wouldn't that be the method to re-create your own copyrightable implementation of GPL code too?
The few exceptions are where copyright essentially doesn't exist at all. Where it does, this is how it works.