Fingerprint Shield is a Firefox privacy WebExtension for browser desktop and Android that detects fingerprinting-like activity, and protects against fingerprinting. It generates a false positive relative to the browser data to prevent any collection for advertising purposes. If a little shield icon appears in the address bar beside the Bookmark icon, it means that the website you are visiting has tried to access the data of at least one canvas, and Fingerprint Shield has blocked it. Clicking on the WebExtension icon (this feature not working in Firefox for Android) will allow you to see how many and which canvases have been blocked.
Add-on description updated 24.09.2019 ### Limitations - WebExtension only works on sites that allow content scripts.
