Here, this one will work without requiring jQuery:

  javascript:(function(){var a=document.getElementsByTagName('img'),i=a.length;while(b=a[--i]){b.setAttribute('src','http://placekitten.com/'+b.width+'/'+b.height);}})();

javascript: void $('img').each(function(i,img) { var $i = $(img), w = $i.width(), h = $i.height(); if ( w && h ) img.src = 'http://placekitten.com/+w+/+h;});

Paste that in foxnews.com!