OBS is willing to work with TikTok to get them into compliance. That would either mean open-sourcing the software or paying for a license.
Of course, now I think about it, that could be an easy problem to fix. They say every man has a number.
A lot of projects have copyright assignment, to allow for relicensing. They typically ask for you to assign copyright to them or to a company they control, so that they can still relicense as they see fit, in future.
no, in general it means TikTok rewriting those portions of the software themselves
That’s why you can use GPL software in your private CI system and not need to give anyone the source code.
Basically, it's practically (not ethically) fair game to use GPL in commercial software, until someone catches you. The only repercussion that the license provides is that your license is revoked until you resolve the violation (for the first violation).
Meanwhile, you got to release your product, and by the time you got caught you've had enough time to implement it yourself.
This also makes sense when you factor in that retaining lawyer services to prosecute the infringement costs time and money (not to mention the court's time & resources to handle the case).
The catch is that the more copyright holders there are the more likely it is that someone who has contributed a non-trivial part of the project will not agree, in which case their work would have to be removed/replaced to allow for relicensing.
Large projects that have not required a CLA from contributors are effectively impossible to relicense.
Often the issue is that some projects don’t require contributors to sign over copyright ownership as part of contributing. So you have a project that’s licensed uniformly, but each contributor still owns their individual contribution. Unwinding this after the fact can be a nightmare, as it involves either finding every contributor and asking them to sign over their code, or manually removing every bit of code you don’t own as a project.
This is why a lot of bigger projects require you sign a contributors agreement that assigns copyright before you can contribute to the main repo. Doing this in advance saves the project a lot of headaches down the road if dual licensing is deemed useful. This is true even if you want to license under two different open source licenses, as only the copyright holder can change the license.