[lal]

Licenses explicitly are the set of permissions and limitations for someone to use the code. Even most permissive open source licenses require that you maintain an attribution with the text of the license in derivative works. Copyleft licenses and in particular the GPL put very strict requirements on what types of licenses are acceptable in any derivative works.

In literally no open source license except "do-whatever-you-want-i-dont-give-a-damn-bye"-type licenses like WTFPL are you giving something away for free without limitations. That's not even close to what open source means, at all. Open source and public domain are not synonymous terms. And in those cases where there are literally any terms in a license, use of Copilot obviously violates the terms of the license, unless the user operating Copilot goes back, finds the code Copilot is stealing from, and makes the proper attribution / otherwise ensures that they are meeting the terms of the license of the stolen code.