This means that a licence violation, in essence, is just a copyright violation.
In other words, if someone e.g. uses GPL'd code in a closed-source product, the offence is the same as if they'd have used non-open source code: a copyright violation.
They were never given permission to use that copyrighted code in a closed-source product in the first place!
This mental model also helps explain how a project can have multiple licences: since they just confer extra rights, they're strictly additive. Users can benefits from the rights granted to them in both licences.
@humanetech Yeah, I was thinking about adding something about the DCO, but decided that would be wading too far into the weeds.
To be clear, the DCO solves a different problem than the one LLVM is running into now: to ensure that those who licence their work take responsibility for being allowed to do so (i.e. that they're the copyright holders). It does not allow an organisation to later re-license that work. (Which, of course, is exactly the reason for going with a DCO over a CLA.)
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