I've created a simple Chrome extension that seeks for certain strings using regex and replaces matches with predefined text. It works well on most websites, but somehow the script doesn't take effect on, for example, Lifehacker (like this page http://lifehacker.com/5939740/five-best-audio-editing-applications?popular=true ). The code is:

$('p, h1, h2, h3, span, .content, .post-body').each(function(){
        //do something with $(this)
});

Any ideas why is Lifehacker's site resistant to my script?