It is the most comprehensive such study ever conducted: more than 144 million page loads were examined during the analysis. The research covered more than 12 countries, including the United States, Canada, Great Britain, France, Germany, Austria and Switzerland.

The study found that at least one tracker was prowling around 77.4 percent of the tested page loads. With the help of cookie or fingerprinting processes, these trackers tag along as users surf the Web, carefully recording their every move. In the most benign cases, this information is used only for statistical and advertising purposes. As a rule, a number of third-party tracking scripts hang out on popular websites, and they hitch a ride with users as they pass through domains. Ten or more trackers that amass personal data were found on 21.3 percent of the sites(unique domains) analyzed in the study.

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The study also identified the most widely used trackers online. Google and Facebook stood out in particular, here. Google ranks in the top ten of the most widely used trackers based on page loads with five services. Facebook has three. Google Analytics was found on nearly half of all loaded pages (46.4 percent). Facebook Connect was on more than a fifth (21.9 percent).