Why does Ghostery need to read and change content on the websites you visit?

When you install Ghostery Lite for the first time, you’ll receive the following message: “Ghostery can read, modify, and transmit content from all web pages. This could include sensitive information like passwords, phone numbers and credit cards.” This text is different depending on which browser you are using, but the intent is the same and is controlled by the browser itself. We can’t change this text in any way.

Why does Ghostery need to read and change content on the websites you visit?

Script/Ad Blockers work by blocking a web page’s requests to download content from the servers that host them. Then, the magic happens. But in order to do that, the extension needs to be able to:

• See every page you open. If Ghostery can’t see the page, it can’t do anything. This means that Ghostery knows the URL (Internet address) of the pages you visit, when you have Ghostery running.

• See all the data on the page to find any unblocked scripts/ads nestled in with the other page data. This also means that Ghostery can see any forms you submit and your browsing history on that tab.

• Have access to modify data on the page. Ghostery changes things around by adding some HTML, CSS, and JavaScript code to the page to block unblocked ads/scripts.

Please know that even though the Ghostery extension can see all these elements of a web page, it does so with user privacy in mind. The extension does not record your browsing history, capture your passwords or bank account numbers, or secretly change data you submit on a web form. It’s important to remember that the warning from the browser is attempting to address all the possible ways an extension may interact with content on a web page. Ghostery is an open source technology and we invite you to take a look and see what we are doing behind the scenes here.