Yahoo Warns Users from Dangerous Search Results
Yahoo! and McAfee have teamed up together to make search results safer. Named as SearchScan (beta), it uses McAfee’s SiteAdvisor database to filter or flag potentially dangerous search results. McAfee SiteAdvisor is actually a free browser add-on to protect users from malicious sites which contains spywares, virus and sell your email addresses. Yahoo has implemented the same SiteAdvisor technology under its hood to protect their search users.

SearchScan works by removing search results which use browser exploits to stealthily harm your computer by just visiting the link. Warnings will be shown next to search results, which potentially offer viruses or adware packed inside screensavers or any other software download. SearchScan will also flag sites which send unsolicited emails or sell your emails address.
You can configure SearchScan from the settings page to never show potentially dangerous sites, or stop SearchScan completely.

Google has a similar initiative called StopBadware which flags malicious sites in search results. Google redirects users to a different page which warns the user about the potential danger instead of just showing warning notes in the search results. However, Google does not flag sites which send unsolicited emails.
[Via: Yahoo! News]