Want to filter out some useless, spammy or offensive sites from Google, DuckDuckGo, Startpage.com, Bing or Yahoo search results? Just click "block" to reduce a site's hits to a one-line notation, or hide it completely. No typing required.
For a one-minute video overview, and a detailed description of the script, please see the following page: http://www.jeffersonscher.com/gm/google-hit-hider/
Before switching, use the Export feature to make a backup copy of your block list. This script will install alongside the old one, and you will need to disable the old one on the Firefox Add-ons page, User Scripts section, or the Tampermonkey Dashboard. Then you can import your block list to the new script.
Firefox 45-56 users: Install the Greasemonkey extension from Mozilla Add-ons BEFORE installing this userscript.
Google Chrome users: Install the Tampermonkey extension from the Chrome store BEFORE installing this userscript.
Other Browsers: I have no idea...
Disclaimer: Google search is a very complex application, so there is no guarantee that this script will work for you. The author is not responsible for you missing a result you might have liked to see, or other malfunction of the script. Use at your own risk.
You can find explanations of most functions on my site here: http://www.jeffersonscher.com/gm/google-hit-hider/. If that does not help, please use the "Issues" link on the toolbar just below the Install button.
v1.8.2 - import can completely replace your current list, tweaks for Yahoo results
v1.8.1 - ability to remove subdomains from partial domain in block form; block featured snippets
v1.8.0 - minor tweak for Google; compatibility with uAutoPagerize on Yahoo and Yahoo Japan
v1.7.9 - initial support for Searx.me metasearch (general/news), minor CSS corrections
v1.7.8 - fix bugs on Google Image results
v1.7.7 - find real domain in Startpage.com highlight links (per the issue: "Inaccurate block popup."), restore GHHbD button on Google Image results
v1.7.6 - adjust placement of the block button to avoid overlaying title or WOT icon
v1.7.5 - work around script change on Google images, initial support for Yandex.com web search
v1.7.4 - fix unblocking bug on Google image search
v1.7.3 - adapt to style change on Google image search
v1.7.2 - tweaked style rules for block button in the cite line on Google
v1.7.1 - adapt to layout change for top result in some Google searches
v1.7.0 - support for Bing and Yahoo web search, various fixes for Google Images, GoogleMonkeyR, style rules
v1.6.9 - partially restore blocking on Google Images (perma-ban results are blank, not deleted)
v1.6.8 - override style rule on DuckDuckGo that truncated the block dialog
v1.6.7 - fixed typo affecting the Autopagerize extension (http://fox.2ch.net/test/read.cgi/poverty/1439688850/99)
v1.6.6 - quick fix for changes to Google web results layout of 7/22/2015
v1.6.5 - updated for current Google images layout, remove blank spots in GoogleMonkeyR layout, fix +site/-site
v1.6.4 - recognize URLs after Google modifies them to tracking links
v1.6.3 - changed @include's from .tld to .*, added detection for In-depth articles section of web results
v1.6.2 - fixes for new DuckDuckGo results layout