Google has switched on a tool that allows web surfers to block searches for sites they don't want to see pop up on the results page.
The stealth algorithm rejig is the latest in a series of changes the Mountain View Chocolate Factory has recently made to its lucrative search estate.
"Now there’s yet another way to find more of what you want on Google by blocking the sites you don’t want to see," said Google's so-called "search quality engineers" Amay Champaneria and Beverly Yang in a blog post yesterday.
Accordingly, the company insisted that the latest tweak was all about empowering the user of its search site.
"We're adding this feature because we believe giving you control over the results you find will provide an even more personalised and enjoyable experience on Google," said Champaneria and Yang.
"In addition, while we're not currently using the domains people block as a signal in ranking, we'll look at the data and see whether it would be useful as we continue to evaluate and improve our search results in the future."
Chillingly for fans of the "free web", that's a statement which suggests Google might yet further refine its search function to effectively whitewash its search results.
So far the feature will only be rolled out to google.com in English for anyone using Chrome 9+, Internet Explorer 8+ and Firefox 3.5+, said the company. It plans to push the algorithm change to other browsers, regions and languages soon.
Surfers need to have a Google account in order to use the tool to kill references to "offensive, pornographic" or "low quality" sites.
Earlier this week, Google penalised its own newly acquired UK price comparison site BeatThatQuote.com, after the firm was found to be violating Mountain View's guidelines about linking.
Last month it made a major change to its search algorithms in order to try to scrub more link farm results from appearing near the top of search results. ®