It's just a procedural formality, although it may aid in preventing content from being removed by aggrieved parties who hadn't intended for it to be made public. (For a few hours, at that one site, maybe.)
Copystriking...oof. There's probably an hour worth of new porn produced ever minute. All the lawyers in the world couldn't hope to keep up with litigating the copyright violations in that area. Interesting prospect though. Would be kind of like trying to clear all the imgflip notifications, only instead of comments it'd be porn, and you'd be getting paid.
I observe copyright laws because I'm such a lawful citizen. 😇 Plus imgflip doesn't need any more reasons to boot me. 😈