15/02/2012 07:44 GMT | Updated 16/04/2012 06:12 BST

Privacy Score Website Tracks How Much your Favourite Sites Know About You

You're careful not to reveal crucial personal details, but if you imagined your life online was in any way totally private, think again.

A new website called Privacy Score ranks most of the major sites you visit, from Google to The Huffington Post, and rates them all for how much they respect your privacy.

Each site gets a privacy rating out of 100, the highest being most private, the lowest being the most likely to share your information.

The site tracks the privacy management of 1,469 major sites on the internet, though many familiar to the UK are not yet tracked., for instance, misses out.

Jim Brock from Privacy Score told The Huffington Post via email: "With the privacy score algorithm, we're boiling down a bunch of complex factors into a guideline that is very easy to understand, and we're putting it right into your browser where you can check it at a glance wherever you might be surfing.

Privacy Score is particularly useful for the majority of web users who don't work online, but want to understand how information moves around the web.

The site aim is to show web users the way that data about you will be used or shared in ways that you probably don't expect.

For instance, many sites track you via advertising and marketing industry trackers like Nielsen, Google Display Network and Omniture.

The information gathered by these trackers is then used by media companies and advertisers to analyse where you go across the web and what you like.

Advertising and other marketing activities are then designed around the information reported by the trackers.

If you were surprised by how each site's privacy score rates, the system has thrown up a few surprises for its founders too.

"One discovery we had is that Facebook privacy is even more complex than we thought. Each game or application page needs its own privacyscore, which is usually lower than the score for the pages with your Timeline or newsfeed. That's because games and apps each have their own privacy policy and in those pages they allow other advertising companies to serve ads and collect data. Without using privacyscore, it's really difficult for you to understand the privacy risk of using all the different parts of Facebook."

They were also shocked at how many retail sites sell your information on.

"We've been amazed at how many sites, particularly in retail, reserve the right to give your personal data to any other company for marketing. With privacyscore you can know this before you give them your personal data, without trying to navigate their privacy policy," he said.

Privacy in the Privacy Score instance is not to be confused with security. The site insists there is nothing in this rating system to suggest that the sites measured lack security.

As with much of the information you willingly place online, the information shared by these site may be personal such as your age, likes and dislikes or the area you live, but the sharing of it is not considered a security concern.

Check out some of the major sites below.