"5. You are not required to accept this License, since you have not signed it. However, nothing else grants you permission to modify or distribute the Program or its derivative works. These actions are prohibited by law if you do not accept this License. Therefore, by modifying or distributing the Program (or any work based on the Program), you indicate your acceptance of this License to do so, and all its terms and conditions for copying, distributing or modifying the Program or works based on it."
The music and movie industries have changed tactics in that they go after the uploader/sender of a copyrighted work. And you would be correct that a simple "oh, sorry, I'll stop sharing that" would probably not suffice to remediate a case that's gone to court - the damage is already done: those that downloaded can't 'unwatch' the movie, and a sale can probably be proven to have been 'lost' as a result.
However, we've seen software copyright cases over source code being remedied in this exact manner. Courts take the type of IP into account. Perhaps a judge might think if the code can simply be replaced without tremendous effort and without drastically affecting the end users' experience, then that infringing piece of software probably wasn't that instrumental in the full app and thus the monetary benefit to the infringer from the infringing code wasn't all that great. Further, in GPL infringement cases, I don't know that the owner could demonstrate damages; we'd be stuck with a punitive award from the court. And here's the rub: GPL hasn't gone to court in the US.
> Perhaps a judge might think if the code can simply be replaced without tremendous effort and without drastically affecting the end users' experience, then that infringing piece of software probably wasn't that instrumental in the full app and thus the monetary benefit to the infringer from the infringing code wasn't all that great.
Exactly. If Wordpress can make a case that the code was integral to Wix's product (maybe even to the point that the product is considered a derived work under copyright law, not just in the GPL sense) or that violating the license gained them an unfair market advantage, they might be able to sue for damages.
"5. You are not required to accept this License, since you have not signed it. However, nothing else grants you permission to modify or distribute the Program or its derivative works. These actions are prohibited by law if you do not accept this License. Therefore, by modifying or distributing the Program (or any work based on the Program), you indicate your acceptance of this License to do so, and all its terms and conditions for copying, distributing or modifying the Program or works based on it."