Google has recently released a browser extension for Chrome users, which allows them to block selected domain names in Google search results. This is truly a helpful extension, specially for those who don’t want to see specific sites in their search results.
Personal Blocklist Chrome Extension
Users can install this new extension from Chrome Web Store. After installing, an option to block domain names will appear on SERPs (see above screenshot).
Google’s Matt Cutts explains, "When you block a site with the extension, you won’t see results from that domain again in your Google search results.". The Personal Blocklist extension is a part of Google’s strategy to detect low-quality websites. Matt says, "extension also sends blocked site information to Google, and we will study the resulting feedback and explore using it as a potential ranking signal for our search results.".
Blekko has already banned several content farms including eHow.