inject rel="noreferer" to all <a> (include dynamically generated)

always-no-referer.user.js

// ==UserScript==
// @name           Always noreferrer links
// @namespace      http://twitter.com/uu59
// @include        *
// ==/UserScript==

(function(){
  var process = function(docroot){
    Array.prototype.forEach.call(
      docroot.querySelectorAll('a'),
      function(a){
        var attr = a.getAttribute('rel') || '';
        if(attr.indexOf('noreferrer') == -1) {
          a.setAttribute('rel', 'noreferrer ' + attr);
        }
      }
    )
  }
  process(document);
  window.addEventListener('DOMNodeInserted', function(e){
    process(e.target.ownerDocument);
  },false);
})();