A few privacy enhancements for browsers

PrivacyGuard.js

// ==UserScript==
// @name         Privacy Guard
// @namespace    https://jumpkick.io/
// @version      1.0.0
// @author       Miles Hingston
// @include      *
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    const allow = {};

    // Remove Referrer
    let referrer = document.querySelector('meta[name="referrer"]');

    while(referrer)
    {
        referrer.parentElement.removeChild(referrer);
        referrer = document.querySelector('meta[name="referrer"]');
    }

    const meta = document.createElement('meta');
    meta.name = 'referrer';
    meta.content = 'no-referrer';
    document.querySelector('head').appendChild(meta);

    // Confirm reads from HTML Canvas
    const toDataURL = HTMLCanvasElement.prototype.toDataURL;

    HTMLCanvasElement.prototype.toDataURL = function()
    {
        allow.toDataURL = allow.toDataURL === undefined ? confirm(`Do you want to allow the domain '${document.domain}' to read from HTML Canvas?`) : allow.toDataURL;

        if(allow.toDataURL)
        {
            return toDataURL.call(this);
        }
    };

    // Mock window.navigator object
    Object.defineProperty(window, 'navigator',
    {
        __proto__: null,
        value:
        {
            doNotTrack: '1',
            language: 'en',
            userAgent: 'Mozilla/5.0'
        },
        writable: false,
        enumerable: false,
        configurable: false
    });

    Object.freeze(window.navigator);
})();