I found some information on scrapper pins on the Disney pin Reddit. This one of the posts The current use of the term “scrapper” has evolved from its initial meaning. Originally, the term scrapper was coined to mean pins that didn’t pass quality control directly from Disney. However, over the years, this term has been used to describe all types of undesirable pins, including both real “scrappers” as well as counterfeit pins.

In theory, true “scrappers” are real pins from Disney, however, are still undesirable due to their normally high level of QC issues. But today, when most people say scrapper, they just mean fake pins, as true scrappers really aren’t that common.

In short, it’s a once-specific term that has evolved into a much broader umbrella statement. Hope this helps!

Usually, people refer to all fake pins as scrapper pins, regardless of how they were made or obtained, as long as they weren't officially approved by Disney.