After flagging search results that distribute malware, Google will also show warnings for web pages used for phishing. Most of these pages are active one or two days before they are taken down by hosting providers, but some of them could be indexed by search engines. While the latest versions of Internet Explorer, Firefox and Opera have anti-phishing protection, a new security layer still have some usefulness.
"Warning - phishing (web forgery) suspected. The site you are trying to visit has been identified as a forgery, intended to trick you into disclosing financial, personal or other sensitive information," mentions the page displayed by Google instead of the search result.
Google also has a Safe Browsing API "that enables client applications to check URLs against Google's constantly updated blacklists of suspected phishing and malware pages." The API is used by Firefox and Google Desktop.