Most search engines already warn you if you try to visit a phishing site.
Microsoft Bing is going one step ahead.
This search engine would warn you if it thinks that you are searching for information related to online scams.
These kind of spam are generally called malvertising.
Microsoft is collaborating with Federal Trade Commission, the United States Postal Inspection Service and Western Union for these public service ads on their Bing search engine.
The aim is to alert the user if he is hunting for information related to some scam aimed at him.