Arizona:

State Bar of Arizona Ethics Opinion 05-04: Electronic Storage; Confidentiality

State Bar of Arizona Ethics Opinion 09-04: Confidentiality; Maintaining Client Files; Electronic Storage; Internet

Iowa:

Iowa State Bar Association Committee on Ethics and Practice Guidelines: Ethics Opinion 11-01: “Use of Software as a Service – Cloud Computing”

Maine:

Maine State Bar Professional Ethics Commission: “Client Confidences: Confidential firm data held electronically and handled by technicians for third-party vendors;” Opinion 194

New Jersey:

New Jersey Bar Advisory Committee on Professional Ethics: “Electronic Storage and Access of Client Files;” Opinion 701

New York:

New York State Bar Association Committee on Professional Ethics: Opinion 842

New York State Bar Association Committee on Professional Ethics: Opinion 820

North Carolina:

North Carolina State Bar Association Proposed 2011 Formal Ethics Opinion 6: “Subscribing to Software as a Service While Fulfilling the Duties of Confidentiality and Preservation of Client Property”

Pennsylvania:

Pennsylvania Bar Association Committee on Legal Ethics and Professional Responsibility: Informal Opinion 2010-60 unfortunately is only available on line to Pennsylvania Bar members.  However, the Spring 2011 issue of At Issue – a publication by and for the Young Lawyers Division of the Pennsylvania Bar Association has an article discussing that opinion: Cloud Computing 101 for Lawyers (pg 8)

Oregon:

Oregon State Bar Association Formal Ethics Opinion Number 2011-188: “Information Relating to the Representation of a Client: Third-Party Electronic Storage of Client Materials“