nothing in the text of the GPLs suggests that third parties have the right to enforce alleged violations of the GPLs. Further, the FSF has made clear that it never intended third-party enforcement, stating publicly that ‘the copyright holders of the software are the ones who have the power to enforce the GPL’ and that ‘[i]f you think you see a violation of the GNU GPL [or] LGPL . . . you should send a precise report to the copyright holders of the packages that are being wrongly distributed . . . [because] we cannot act on our own where we do not hold copyright.

Vizio also argued that GPL is a software license, not a contract, so the company has no contractual obligation to provide SFC with Vizio OS’s source code, even if SFC were considered a third-party beneficiary of GPLv2 LGPLv2.

anathema

Afaik, any use of (non-L)GPL code in your project requires you to open the code you add to it as GPL as well