This add-on automatically removes all garbage like "utm_source=*" from URLs. These fields are provided for the Google Analytics and they are not a necessity. Example of URL with garbage fields: http://bigpicture.ru/?p=431513&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+bigpictures+%28%D0%9D%D0%9E%D0%92%D0%9E%D0%A1%D0%A2%D0%98+%D0%92+%D0%A4%D0%9E%D0%A2%D0%9E%D0%93%D0%A0%D0%90%D0%A4%D0