From a BBC article on a new Google feature that will alert web surfers about unsafe web sites –

Google has started warning users if they are about to visit a webpage that could harm their computer.

The warning will pop up if users click on a link to a page known to host spyware or other malicious programs.

The initiative comes out of a larger project cataloguing programs that plague people with unwanted ads, spy on web habits or steal personal data.

Google is one of several companies trying to act as an “in-flight adviser” to ensure people stay safe online.

You can read the entire article @ Google warns on ‘unsafe’ websites.