@namespace url(http://www.w3.org/1999/xhtml);

@-moz-document domain("live.com") {
  #c_or_msncontent, #c_msncontent_feed1, #c_msncontent_feed2, #c_msncontent_feed3, #c_msncontent_feed4, 
  #Ad300x250, .adRow, #adPlacement, #AdContainer {display:none !important;}
}