There are some parasite websites whose “content” are entirely made up of material scraped from other sites. This is, of course illegal copyright infringement. But unless you have unlimited time and resources, it is almost impossible to do anything about it. Scraper sites are typically created to generate revenue by advertising. They can be highly profitable because the owner does not spend any resources creating content. Instead the owner spends some of his ill-gotten proceeds on SEO, achieving higher search engine rankings than the sites of the content makers from whom they scrape their material. Thus scraper sites rob original content cretors traffic and revenue.
Google is testing algorithmic changes for scraper sites (especially blog scrapers). We are asking for examples, and may use data you submit to test and improve our algorithms.
It is a good start, and if any of my readers come across a typical scraper site, I hope you will take the time to report it to Google.