Here's a list of urls that are probably the ones that are filtered. I looked through the first 4 pages of results returned for the query that crymeph0 linked to, and didn't see any of the urls on that list (other than www.xenu.net/) The number of results that the message at the bottom says were removed changes on each page of the results too.
https://pi-hole.net/
The CustomizeGoogle extension for Firefox allows you to blacklist sites from search results.
http://audio.textfiles.com/shows/geeksinspace/
Here's a list of urls that are probably the ones that are filtered. I looked through the first 4 pages of results returned for the query that crymeph0 linked to, and didn't see any of the urls on that list (other than www.xenu.net/) The number of results that the message at the bottom says were removed changes on each page of the results too.
Linux