Grease Monkey script to remove (=make less visible) texts which contains unwanted keywords. This specific version removes Olympic related words on nikkei.com.

OlympicRemover.js

// ==UserScript==
// @name        OlympicRemover
// @namespace   http://yattom.jp/experimental
// @include     http://www.nikkei.com/
// @version     1
// ==/UserScript==


var org_func = window.onload();

window.onload = function() {
  var remove = function() {
    var keywords = [
      '五輪',
      'オリンピック',
    ];
    var handle = function(tag) {
      for(var i in tag.childNodes) {
        var e = tag.childNodes[i];
        if(e.nodeType == document.TEXT_NODE) {
          found = false;
          for(j in keywords) {
            if(e.textContent.indexOf(keywords[j]) != -1) {
              found = true;
              break;
            }
          }
          if(!found) {
            return false;
          }
          tag.style['opacity'] = 0.1;
          //tag.style['background'] = 'red';
          return true;
        }
      }
      return false;
    };

    var traverse = function(element, fn) {
      var skipChildren = fn(element);
      if(skipChildren) { return; }
      for(var i in element.children) {
        traverse(element.children[i], fn);
      }
    };

    traverse(document.body, handle);
  };

  window.setTimeout(remove, 3 * 1000);
  window.setInterval(remove, 3 * 60 * 1000);
  org_func();
}