Local Sheriff is a browser extension for Google Chrome and Mozilla Firefox that reveals to you if sites you visit share or leak personal information with third-parties.
The main difference between Local Sheriff and extensions that list trackers on websites is that Local Sheriff may reveal the actual data that gets shared with third-parties.
Websites that you visit may share or leak all sorts of personal information with third-party sites that connections get established to on it.
Sites you visit may leak personal information unknowingly or knowingly. Personal information may be found in web addresses (URLs), on-page content, or as data entered in web forms. URLs may include names, email addresses, or other personal information.
The data may be shared through various automated mechanisms. Examples include through HTTPS Headers when establishing connections, using query parameters, or browser features.
https://github.com/cliqz-oss/local-sheriff