If this whole thing has you feeling a sense of déjà vu, don't worry: You aren't losing your mind. Google a similar search-filtering feature about a month ago in the form of an . The extension did almost the same exact thing as this new feature, except for the fact that it worked on the browser-level instead of on Google's own servers.

It's all part of Google's steady efforts to combat the presence of search spam -- a fancy term for low-quality entries that show up in search results. Google has increasingly come under fire for search spam in recent weeks, with and pundits saying the company's level of search-result junk is spiraling out of control. The concerns revolve largely around so-called "content farms," or sites that generate lots of pages with little real value. Many of these sites monitor popular search queries and create pages for the sole purpose of attracting traffic, even though they have no original or relevant content to offer.

Google also recently to try to keep those sites from cluttering up results. The change, announced in late February, is designed to and give higher rankings to sites with more original and in-depth material.