Recent　advances　in　cloud　computing　technology　now　allow　users　to　access　data　wherever　they　are.　However,　with　these　advances　come　some　costs:　cloud　data　is　often　stored　and　manipulated　by　remote　machines　that　users　have　no　access　to.　Moreover,　cloud　service　providers　often　claim　that　their　data　is　safe　and　secure,　but　users　rarely　have　ways　to　make　sure.　Based　on　recent　academic　and　industrial　research,　this　paper　surveys　various　approaches　cloud　service　companies　can　make　to　ensure　proper　accountability.　The　paper　focuses　on　issues　such　as　cloud　accountability　framework,　data　confidentiality,　and　user　privacy.　More　importantly,　we　also　put　forth　some　efficiency　advice.