Most of us use the Internet and assume that we’re protected from our personal information being shared with others. That’s not always the case as we’ve found, especially when it comes to companies tracking our activity to share with advertisers. One can change the privacy settings in our browser or click on the privacy icon that many display ads carry.

To find out what is really going on under the pages of many Web sites and the third-party ad networks they work with, however, users would have to take a more difficult route — reading the privacy policy for each Web site in detail. Buried deep within the legalese used in many privacy policies is information on how Web publishers collect and handle the data they use to show ads to their visitors.

PrivacyChoice, a company that has analyzed and indexed the data in hundreds of privacy policies across the Web, has developed a system to score Web sites on a scale of 0 to 100 based on how a site collects and uses personal data.

The tool’s algorithm gives points to sites for various activities — such as 30 points if the site does not share personal data such as names, e-mail addresses and phone numbers, 10 points if the site deletes data promptly when a user closes an account and 5 points if the site notifies users when government agencies request user data from them. Third-party companies — such as advertisers — receive 20 points if they don’t associate identification data with your web activity, 5 points if they don’t collect data on sensitive areas such as health history and financial records.

“For the first time, Web publishers and their users have a way to easily compare privacy practices across the Web,” said Jim Brock, the founder of PrivacyChoice, in a statement. “This transparency not only allows people to make smarter decisions about their own data, it also will spur more protective privacy practices by sites and tracking companies, which is long overdue.”

The service is currently tracking 1,508 websites on how they share personal data, delete data when a user asks it to, accessible legal disclosures, opt-out capabilities, and how long it retains user data.

You can also download a plug-in for their browsers (Firefox, Chrome) that, when activated, will show a privacy score at the top of each Web site they visit. When you click on a site’s score you are shown a few details with a link to Privacyscore’s full report:

Moreover Privacyscore displays top ten list of sites that have the most number of trackers installed on its pages. This means that these sites are using advertisements that are tracking your surfing habits.