KerntEvents.user.js

// ==UserScript==
// @name         Kernt Events
// @version      1
// @description  Make all the kerning bad
// @author       NickyNouse
// @match        *://*/*
// @grant        none
// ==/UserScript==
'use strict';
//from http://stackoverflow.com/a/29301739/1784306
var matchText = function(node, regex, callback, excludeElements) { 
    excludeElements || (excludeElements = ['krn', 'script', 'style', 'iframe', 'canvas', 'textarea']);
    var child = node.firstChild;

    while (child) {
        switch (child.nodeType) {
        case 1:
            if (excludeElements.indexOf(child.tagName.toLowerCase()) > -1)
                break;
            matchText(child, regex, callback, excludeElements);
            break;
        case 3:
            var bk = 0;
            child.data.replace(regex, function(all) {
                var args = [].slice.call(arguments),
                    offset = args[args.length - 2],
                    newTextNode = child.splitText(offset+bk), tag;
                bk -= child.data.length + all.length;

                newTextNode.data = newTextNode.data.substr(all.length);
                tag = callback.apply(window, [child].concat(args));
                child.parentNode.insertBefore(tag, newTextNode);
                child = newTextNode;
            });
            break;
        }
        child = child.nextSibling;
    }

    return node;
};

matchText(document.body, /\w\w/g, function(node, match, offset) {
    var span = document.createElement("krn");
    span.style.letterSpacing = (0.17*(Math.random() - .5)) + "em";
    span.textContent = match;
    return span;
});