Of course laws vary, and Polish copyright law might be completely crazy, but around here copyright only covers distribution of copies. It does not make it illegal to modify software that you own. It only limits distribution of copies of that software, modified or otherwise. If the owner of the train wants to modify the software then there is probably nothing stopping them.
I don't know anything about Polish law either, but in the US, copyright law (DMCA in particular) makes it illegal to modify the software in a device you own, if it requires circumventing protection code or devices. Which it probably would in this case.
According to the Polish copyright law, by default one can reverse engineer and modify licensed software without author's permission to ensure interoperability with other software and for fixing bugs. Such right can be explicitly denied by the copyright owner, though.
But could the authors be attacked for treason, destruction of property, or a simili-Patriot Act? Besides, have we learnt something about any public software being required to be delivered as open-source?
> If the owner of the train wants to modify the software then there is probably nothing stopping them.
This of assumes that the owner of the train company has the skills to do this. In reality they probably would need outside help and that company might fall foul of copyright issues. (when they are distributing the modified code back to the train company, for example)
But the real problem of course is that all of this code is very likely safety critical. Can they modify it? Probably. Is it a good idea? Not really.
As a CEO of a railway company, not sure I'd want folks to patch the binaries on my trains. Pretty sure an insurance company wouldn't like that in case shit happens.
Rather, the companies with botched trains should demand from Newag to remove their locks, for free, and on the side sue them.
