Tampermonkey script to prevent websites from tracking you using favicon fingerprinting

Defeat supercookie.js

// ==UserScript==
// @name         Defeat supercookie (https://github.com/jonasstrehle/supercookie)
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Prevent websites from tracking you using favicon fingerprinting
// @author       Luke Pothier <[email protected]>
// @match        https://*/*
// @match        http://*/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    onDocumentReady(function() {
        let req = new XMLHttpRequest();
        req.open('GET', getFavicon(), true);
        req.send(null);
    });
})();

function onDocumentReady(func) {
    if (document.readyState === 'complete' || document.readyState === 'interactive') {
        setTimeout(func, 1);
    } else {
        document.addEventListener('DOMContentLoaded', func);
    }
}

function getFavicon() {
    let favicon = window.location.origin + '/favicon.ico';
    let nodes = document.getElementsByTagName('link');

    for (let i = 0; i < nodes.length; i++)
    {
        if((nodes[i].getAttribute('rel') === 'icon') ||
           (nodes[i].getAttribute('rel') === 'shortcut icon'))
        {
            favicon = nodes[i].getAttribute('href');
        }
    }

    return favicon;
}