The Don't Be Evil tool is a bookmarklet created by engineers at Facebook, Twitter and MySpace and released in January 2011. The tool allows those using the Google search engine to modify three parts of Google's Search Plus Your World results, which critics say favor Google+ pages. Users can download the Don't Be Evil button as a bookmark in their browser bar. When the button is clicked after conducting a Google search, it modifies the Google search results to promote results from older, more established social networking sites. As of 2012, these profiles tend to have more followers than Google+ pages. As such, the creators of the Don't Be Evil tool believe these results may be more relevant.
Techopedia explains Don't Be Evil Tool
The Don't Be Evil tool works best in searches for general interest topics, such as sports, music or technology. These searches often deliver a right-hand column titled "People and Pages From Google+". Clicking the Don't Be Evil button modifies these results, calling them "People and Pages from the Social Web." This produces results that may promote Twitter, Facebook and other social networking sites above Google+. Clicking the button also modifies the Google logo to read "What Google Should Be."
Don't Be Evil uses Google's algorithms to determine which social media results appear at the top of the column. So, if you run a Google search for rap musician Snoop Dogg, for example, you'll notice that his Twitter account appears far above his Google+ search results. This means that clicking the Don't Be Evil button will also push his Twitter account to the top of the "People and Pages from the Social Web" column.