How this works?
Google has been getting requests from various copywriters(since years) to de-rank the websites that have copied their content, and rank above them. Finally, they have accepted the requests from millions of original copywriters and have included a signal that considers DMCA claims to rank a website in Google.
How this gonna affect you?
If your blog/ website has copied a content, and if the original author claims the content at DMCA, Google will consider that claim and can de-rank your website in search engine. Google has also stated that, the website will not be de-indexed but only de-ranked.
However, Google has not given any clarification on how the webmaster would be made aware when their website is claimed for copying content