userscript: Drop the UTM params from a URL when the page loads

utmstrip.user.js

// ==UserScript==
// @name          UTM param stripper
// @author        Paul Irish
// @namespace     http://github.com/paulirish
// @description   Drop the UTM params from a URL when the page loads.
// @extra         Cuz you know they're all ugly n shit.
// @include       http://*
// ==/UserScript==

// save this as utmstrip.user.js and drag it into Chrome or Firebug (with greasemonkey)

var oldUrl = location.href;
var newUrl = oldUrl.replace(/\?([^#]*)/, function(_, search) {
  search = search.split('&').filter(function(v) {
    return !/^utm_/.test(v);
  }).join('&');
  return search ? '?' + search : '';
});

if ( newUrl != oldUrl ) {
  window.history.replaceState({}, '', newUrl);
}