Is Facebook supposed to scan all Twitter everytime you post something to check if it's not violating the copyright of someone there? To know every paragraph of

Is Facebook supposed to scan all Twitter everytime you post something to check if it's not violating the copyright of someone there? To know every paragraph of every single book? Or scan the entire internet for that matter? That is not "lazy", that is just a ridiculous expectation, no (legal) social network would survive if that was necessary to operate Not to mention the millions of derivative works where the definition gets fuzzy: I applied a filter to someone else photo and put an emoji over it, is still the same work? Should FB algorithm be smart enough to classify it as a copyright violation? It would be unsustainable economically to run that algorithm against the millions of posts, and even if they told the user "stop! that is copyrighted!" a huge chunk of users would just edit their post a bit and just try again.