It wasn't about copyright or fair use, at least not directly. The intended purpose of this sort of code was to: 1. Make sure many people who shared content fro

It wasn't about copyright or fair use, at least not directly. The intended purpose of this sort of code was to: 1. Make sure many people who shared content from your site would link back to the source 2. Track shares where the full link to the page wasn't copied 3. Trick scrapers/careless plagiarists into linking back to the original source, using their own carelessness to get an extra backlink or two (and tell Google your site was the original). All of these obviously only worked on people that didn't check what they were copying, but hey, those were some of the reasons behind it.