A new study from Ghostery, an anti-tracking tool, shows that an overwhelming majority (79%) of websites globally are tracking visitors' data — with 10% of these sites actually sending user data to 10 companies or more.

Why it matters: Trackers can collect and sell visitor data in ways that aren't always obvious to consumers. Too many trackers can also slow down website load times. As the trade war for data intensifies, companies that collect the most data through trackers will become the biggest targets of data privacy reform.

Expand chart Reproduced from Ghostery; Chart: Axios Visuals

Tr acking scripts from Google a n d Facebook a re by far the most pervasive. Together, those two companies collect more data than most other companies combined.

n re by far the most pervasive. Together, those two companies collect more data than most other companies combined. Th e U.S., Russia and U.K. have more trackers p er page load than the global average, while Germany, France and India have fewer. (Germany and many European countries are known for their culture of strong data privacy.)

er page load than the global average, while Germany, France and India have fewer. (Germany and many European countries are known for their culture of strong data privacy.) The advertising supply chain represents the vast majority of tracking companies.

New regulatory efforts to protect consumer privacy will significantly hinder these companies' ability to collect data via tracking scripts. The General Data Protection Regulation (GDPR), which goes into effect next year in Europe, will require companies to get explicit permission from consumers to collect their data.

Too many trackers can often create slower web experiences. A Princeton study earlier this year found that mainstream news websites use more third-party ad tech vendors than any other type of website: sports, shopping, adult, etc. Such partnerships can slow down load times for publisher sites if there are too many trackers dropped on a page, or if they're using certain techniques to capture data.

So me of the more heavily-trafficked user websites ar e trying to peel back on these partnerships to speed up their sites. Bloomberg, The Washington Post and others have made significant efforts to curb the number of tracking scripts on their web-pages in an effort to keep their sites nimble.

e trying to peel back on these partnerships to speed up their sites. Bloomberg, The Washington Post and others have made significant efforts to curb the number of tracking scripts on their web-pages in an effort to keep their sites nimble. So me websites use "redirect" buttons th at allow users to post content to social media without giving those sites direct access to their first-party data that they could monetize. Sites may still share data with these platforms in other ways, however.

at allow users to post content to social media without giving those sites direct access to their first-party data that they could monetize. Sites may still share data with these platforms in other ways, however. Nealy one third of websites tracked has a hidden Facebook tracker, per Ghostery's whotracksme.com site. Facebook won a critical privacy lawsuit in July over tracking users' internet activity through "like" button trackers even after they logged out of the social media website, per Reuters.

Our thought bubble: It benefits these ad companies to have as access to as much data as possible, not just for profit, but because they want to provide better advertising experiences for users. (Studies have shown that consumers prefer customized ads.) Some may argue it's the cost of having free access to their tools.

Methodology: The data was collected by the Ghostery browser extension's GhostRank feature and covers all major browsers (Firefox, Chrome, Edge, Opera, and the Ghostery Privacy Browser for iOS and Android). It encompasses the internet activity of 850,000 internet users internationally across 440 million page loads.