Mo. R. Gov. Bar Jud. 4-1.6
 This Rule 4-1.6 governs the disclosure by a lawyer of information relating to the representation of a client during the lawyer's representation of the client. See Rulefor the lawyer's duties with respect to information provided to the lawyer by a prospective client, Rule for the lawyer's duty not to reveal information relating to the lawyer's prior representation of a former client, and Rules and for the lawyer's duties with respect to the use of such information to the disadvantage of clients and former clients.
 A fundamental principle in the client-lawyer relationship is that, in the absence of the client's informed consent, the lawyer must not reveal information relating to the representation. See Rule 4-1.0(e) for the definition of "informed consent." This contributes to the trust that is the hallmark of the client-lawyer relationship. The client is thereby encouraged to seek legal assistance and to communicate fully and frankly with the lawyer even as to embarrassing or legally damaging subject matter. The lawyer needs this information to represent the client effectively and, if necessary, to advise the client to refrain from wrongful conduct. Almost without exception, clients come to lawyers in order to determine their rights and what is, in the complex of laws and regulations, deemed to be legal and correct. Based upon experience, lawyers know that almost all clients follow the advice given, and the law is upheld.
 The principle of client-lawyer confidentiality is given effect by related bodies of law: the attorney-client privilege, the work-product doctrine, and the rule of confidentiality established in professional ethics. The attorney-client privilege and work-product doctrine apply in judicial and other proceedings in which a lawyer may be called as a witness or otherwise required to produce evidence concerning a client. The rule of client-lawyer confidentiality applies in situations other than those where evidence is sought from the lawyer through compulsion of law. The confidentiality rule, for example, not only applies to matters communicated in confidence by the client, but also to all information relating to the representation, whatever its source. A lawyer may not disclose such information except as authorized or required by the Rules of Professional Conduct or other law. See also Scope.
 Rule 4-1.6(a) prohibits a lawyer from revealing information relating to the representation of a client. This prohibition also applies to disclosures by a lawyer that do not in themselves reveal protected information but could reasonably lead to the discovery of such information by a third person. A lawyer's use of a hypothetical to discuss issues relating to the representation is permissible so long as there is no reasonable likelihood that the listener will be able to ascertain the identity of the client or the situation involved.
 Except to the extent that the client's instructions or special circumstances limit that authority, a lawyer is impliedly authorized to make disclosures about a client when appropriate in carrying out the representation. In some situations, for example, a lawyer may be impliedly authorized to admit a fact that cannot properly be disputed or to make a disclosure that facilitates a satisfactory conclusion to a matter. Lawyers in a firm may, in the course of the firm's practice, disclose to each other information relating to a client of the firm, unless the client has instructed that particular information be confined to specified lawyers.
Disclosure Adverse to Client.
 Although the public interest is usually best served by a strict rule requiring lawyers to preserve the confidentiality of information relating to the representation of their clients, the confidentiality rule is subject to limited exceptions. Rule 4-1.6(b)(1) recognizes the overriding value of life and physical integrity and permits disclosure reasonably necessary to prevent reasonably certain death or substantial bodily harm. Such harm is reasonably certain to occur if it will be suffered imminently or if there is a present and substantial threat that a person will suffer such harm at a later date if the lawyer fails to take action necessary to eliminate the threat. Thus, a lawyer who knows that a client has accidentally discharged toxic waste into a town's water supply may reveal this information to the authorities if there is a present and substantial risk that a person who drinks the water will contract a life-threatening or debilitating disease and the lawyer's disclosure is necessary to eliminate the threat or reduce the number of victims.
 A lawyer's confidentiality obligations do not preclude a lawyer from securing confidential legal advice about the lawyer's personal responsibility to comply with these Rules. In most situations, disclosing information to secure such advice will be impliedly authorized for the lawyer to carry out the representation. Even when the disclosure is not impliedly authorized, Rule 4-1.6(b)(2) permits such disclosure because of the importance of a lawyer's compliance with the Rules of Professional Conduct.
 Where a legal claim or disciplinary charge alleges complicity of the lawyer in a client's conduct or other misconduct of the lawyer involving representation of the client, the lawyer may respond to the extent the lawyer reasonably believes necessary to establish a defense. The same is true with respect to a claim involving the conduct or representation of a former client. Such a charge can arise in a civil, criminal, disciplinary, or other proceeding and can be based on a wrong allegedly committed by the lawyer against the client or on a wrong alleged by a third person, for example, a person claiming to have been defrauded by the lawyer and client acting together. The lawyer's right to respond arises when an assertion of such complicity has been made. Rule 4-1.6(b)(3) does not require the lawyer to await the commencement of an action or proceeding that charges such complicity, so that the defense may be established by responding directly to a third party who has made such an assertion. The right to defend also applies, of course, where a proceeding has been commenced.
 A lawyer entitled to a fee is permitted by Rule 4-1.6(b)(3) to prove the services rendered in an action to collect it. This aspect of the rule expresses the principle that the beneficiary of a fiduciary relationship may not exploit it to the detriment of the fiduciary.
 Other law may require that a lawyer disclose information about a client. Whether such a law supersedes Rule 4-1.6 is a question of law beyond the scope of these Rules. When disclosure of information relating to the representation appears to be required by other law, the lawyer must discuss the matter with the client to the extent required by Rule. If, however, the other law supersedes this Rule and requires disclosure, Rule 4-1.6(b)(4) permits the lawyer to make such disclosures as are necessary to comply with the law.
 A lawyer may be ordered to reveal information relating to the representation of a client by a court or by another tribunal or governmental entity claiming authority pursuant to other law to compel the disclosure. Absent informed consent of the client to do otherwise, the lawyer should assert on behalf of the client all nonfrivolous claims that the order is not authorized by other law or that the information sought is protected against disclosure by the attorney-client privilege or other applicable law. In the event of an adverse ruling, the lawyer must consult with the client about the possibility of appeal to the extent required by Rule. Unless review is sought, however, Rule 4-1.6(b)(4) permits the lawyer to comply with the court's order.
 Rule 4-1.6(b) permits disclosure only to the extent the lawyer reasonably believes the disclosure is necessary to accomplish one of the purposes specified. Where practicable, the lawyer should first seek to persuade the client to take suitable action to obviate the need for disclosure. In any case, a disclosure adverse to the client's interest should be no greater than the lawyer reasonably believes necessary to accomplish the purpose. If the disclosure will be made in connection with a judicial proceeding, the disclosure should be made in a manner that limits access to the information to the tribunal or other persons having a need to know it, and appropriate protective orders or other arrangements should be sought by the lawyer to the fullest extent practicable.
 Rule 4-1.6(b) permits but does not require the disclosure of information relating to a client's representation to accomplish the purposes specified in Rule 4-1.6(b)(1) to (b)(4). In exercising the discretion conferred by this Rule 4-1.6, the lawyer may consider such factors as the nature of the lawyer's relationship with the client and with those who might be injured by the client, the lawyer's own involvement in the transaction, and factors that may extenuate the conduct in question. A lawyer's decision not to disclose as permitted by Rule 4-1.6(b) does not violate this Rule 4-1.6. Disclosure may be required, however, by other Rules. Some Rules require disclosure only if such disclosure would be permitted by Rule 4-1.6(b). See Rules, , , and . Rule , on the other hand, requires disclosure in some circumstances regardless of whether such disclosure is permitted by this Rule. See Rule .
 If the lawyer's services will be used by the client in materially furthering a course of criminal or fraudulent conduct, the lawyer must withdraw, as stated in Rule. After withdrawal, the lawyer is required to refrain from making disclosure of the client's confidences, except as otherwise permitted in this Rule 4-1.6. Neither this Rule 4-1.6 nor Rule nor Rule prevents the lawyer from giving notice of the fact of withdrawal, and the lawyer may also withdraw or disaffirm any opinion, document, affirmation, or the like. Where the client is an organization, the lawyer may be in doubt whether contemplated conduct will actually be carried out by the organization. Where necessary to guide conduct in connection with this Rule 4-1.6, the lawyer may make inquiry within the organization as indicated in Rule .
Acting Competently to Preserve Confidentiality
 Paragraph (c) requires a lawyer to act competently to safeguard information relating to the representation of a client against unauthorized access by third parties and against inadvertent or unauthorized disclosure by the lawyer or other persons who are participating in the representation of the client or who are subject to the lawyer's supervision. See Rules, , and . The unauthorized access to, or the inadvertent or unauthorized disclosure of, information relating to the representation of a client does not constitute a violation of paragraph (c) if the lawyer has made reasonable efforts to prevent the access or disclosure. Factors to be considered in determining the reasonableness of the lawyer's efforts include, but are not limited to, the sensitivity of the information, the likelihood of disclosure if additional safeguards are not employed, the cost of employing additional safeguards, the difficulty of implementing the safeguards, and the extent to which the safeguards adversely affect the lawyer's ability to represent clients (e.g., by making a device or important piece of software excessively difficult to use). A client may require the lawyer to implement special security measures not required by this Rule or may give informed consent to forgo security measures that would otherwise be required by this Rule. Whether a lawyer may be required to take additional steps to safeguard a client's information in order to comply with other law, such as state and federal laws that govern data privacy or that impose notification requirements upon the loss of, or unauthorized access to, electronic information, is beyond the scope of these Rules. For a lawyer's duties when sharing information with nonlawyers outside the lawyer's own firm, see Rule , Comments -.
 When transmitting a communication that includes information relating to the representation of a client, the lawyer must take reasonable precautions to prevent the information from coming into the hands of unintended recipients. This duty, however, does not require that the lawyer use special security measures if the method of communication affords a reasonable expectation of privacy. Special circumstances, however, may warrant special precautions. Factors to be considered in determining the reasonableness of the lawyer's expectation of confidentiality include the sensitivity of the information and the extent to which the privacy of the communication is protected by law or by a confidentiality agreement. A client may require the lawyer to implement special security measures not required by this Rule or may give informed consent to the use of a means of communication that would otherwise be prohibited by this Rule. Whether a lawyer may be required to take additional steps in order to comply with other law, such as state and federal laws that govern data privacy, is beyond the scope of these Rules.
 The duty of confidentiality continues after the client-lawyer relationship has terminated. See Rule. See Rule for the prohibition against using such information to the disadvantage of the former client.
 Paragraph (b)(5) recognizes that lawyers in different firms may need to disclose limited information to each other to detect and resolve conflicts of interest, such as when a lawyer is considering an association with another firm, two or more firms are considering a merger, or a lawyer is considering the purchase of a law practice. See Rule, Comment . Under these circumstances, lawyers and law firms are permitted to disclose limited information, but only once substantive discussions regarding the new relationship have occurred. Any such disclosure should ordinarily include no more than the identity of the persons and entities involved in a matter, a brief summary of the general issues involved, and information about whether the matter has terminated. Even this limited information, however, should be disclosed only to the extent reasonably necessary to detect and resolve conflicts of interest that might arise from the possible new relationship. Moreover, the disclosure of any information is prohibited if it would compromise the attorney-client privilege or otherwise prejudice the client (e.g., the fact that a corporate client is seeking advice on a corporate takeover that has not been publicly announced; that a person has consulted a lawyer about the possibility of divorce before the person's intentions are known to the person's spouse; or that a person has consulted a lawyer about a criminal investigation that has not led to a public charge). Under those circumstances, paragraph (a) prohibits disclosure unless the client or former client gives informed consent. A lawyer's fiduciary duty to the lawyer's firm may also govern a lawyer's conduct when exploring an association with another firm and is beyond the scope of these Rules.
 Any information disclosed pursuant to paragraph (b)(5) may be used or further disclosed only to the extent necessary to detect and resolve conflicts of interest. Paragraph (b)(5) does not restrict the use of information acquired by means independent of any disclosure pursuant to paragraph (b)(5). Paragraph (b)(5) also does not affect the disclosure of information within a law firm when the disclosure is otherwise authorized, see Comment , such as when a lawyer in a firm discloses information to another lawyer in the same firm to detect and resolve conflicts of interest that could arise in connection with undertaking a new representation.