Metadata and Mining

Rule 4.4(b) asks one thing of a lawyer who receives a document or ESI relating to the representation of the lawyer's client and knows or reasonably should know that it was inadvertently sent: prompt notice to the sender.¹ Comment 2 reaches embedded data. It defines “document or ESI” to include metadata, the hidden information about a document's creation and revision that software stores inside the file, so long as the data can be read or put into readable form. Metadata creates an obligation under the rule only if the receiving lawyer knows or reasonably should know that it was inadvertently sent.² That is the same knowledge condition that governs a misdirected email or a stray page. What differs is the kind of content it must be applied to.

Metadata behaves differently from an email sent to the wrong address. Word-processing programs record it automatically, and most of it is harmless: when a document was created, when it was revised, and by whom. If the sender used tracked changes or margin comments, though, the file can carry earlier drafts and candid evaluations, and at worst it exposes the client's bottom line in a settlement offer or a deal negotiation.³ The sender may not know that any of this travels with the file, and the recipient will never see it without consciously deciding to search for it.⁴ A lawyer who opens a misdirected email learns of the mistake from what is plainly on the screen, and that knowledge triggers the notice duty. Hidden metadata surfaces only through a deliberate search, which some observers regard as an unseemly practice.⁵ Searching a document's underlying data for hidden or embedded information is called mining.⁶ Whether a lawyer may mine is the question the commentary leaves open, because Comment 2 does not resolve the controversy over whether a lawyer may look at metadata that was inadvertently produced.⁷

The authorities answer that question in three ways, and none of the answers appears in the Model Rule's text. The ABA's Committee on Ethics and Professional Responsibility, in Formal Opinion 06-442, read Rule 4.4(b) as requiring only notice of inadvertently disclosed metadata and as setting no other specific restrictions on the receiving lawyer's conduct.⁸ State ethics authorities have gone in opposite directions because they read Rule 4.4(b) and its commentary differently.⁹ Some treat the search as unethical, others find nothing in the rules that forbids it, and a third group adopts neither absolute position.¹⁰ ABA formal opinions have no precedential weight, though courts and jurisdictions without an opinion of their own often look to them for guidance.¹¹ A lawyer's obligations therefore depend on the jurisdiction where the lawyer practices, and counting jurisdictions on each side will not settle an exam answer.

The disagreement persists because both sides can point to a real interest. A sender who never knew the data existed made a mistake that the recipient can exploit only by choosing to look, and the protection of confidences, privilege, and work product argues for restraint. The rule says nothing about reviewing or using what a recipient receives, and a lawyer has an interest in examining thoroughly everything the other side sent, so the rule's silence argues for permitting the search. Any metadata question therefore starts with the lawyer's jurisdiction, and the notice duty, which applies everywhere, then turns on what the lawyer knew. The prohibitionist position comes first.

Mining as Unethical

The prohibitionist view holds that a lawyer who actively searches an adversary's electronic document for embedded metadata acts unethically. Rule 4.4(b) says nothing about searching for hidden data,¹² so the view comes from outside the rule: it rests on state ethics opinions that reason from their own jurisdictions' professional rules.¹³ New York was among the first to take up the question.

In 2001 the New York State Bar Committee on Professional Ethics concluded in Opinion 749 that mining metadata is unethical because the information found “may be protected by the attorney-client privilege, the work product doctrine or … may otherwise constitute a ‘secret’ of another lawyer’s client [that] would violate the letter and spirit of these Disciplinary Rules.”¹⁴ The opinion's premise is that hidden data may be protected material. A file that carries tracked changes and margin comments can hold earlier drafts and candid evaluations by the sender's lawyer, which is the kind of material the privilege, the work-product doctrine, and the protection of client secrets exist to shield.¹⁵ A search can therefore expose protected material the sender never meant to hand over, and the opinion treats the deliberate search for it as a violation.

Alabama, Arizona, Florida, Maine, and North Carolina reached the same position.¹⁶ North Carolina's 2009 Ethics Opinion 1 adds a second reason. A lawyer who is “actively searching for such information” “interferes with the client-lawyer relationship of another lawyer and undermines the confidentiality that is the bedrock of the relationship.”¹⁷ The two opinions look at different harms. New York looks at what the search turns up, which is protected material belonging to someone else's client. North Carolina looks at what the act of searching does to the other lawyer's relationship with that client.

The prohibition targets the search because metadata, unlike a misdirected email, reaches the recipient only through a deliberate act. An email recipient discovers the mistake from what is plainly on the screen. Hidden metadata never appears unless the recipient consciously decides to look for it,¹⁸ so the discovery leaves no innocent first look, and the sender may have had no idea the file carried the data at all.¹⁹ The prohibitionist states respond by treating the search itself as the wrong.

These opinions rest on each state's own rules and reasoning, and they do not rest on the text of Rule 4.4(b), which requires only notice. The ABA's Formal Opinion 06-442 read the Model Rule as requiring notice and imposing no other specific restriction on the receiving lawyer's conduct.²⁰ On an exam, a stem that places the lawyer in a state with a prohibitionist opinion makes the search a violation of that state's ethics rules. A stem that names no jurisdiction calls for a narrower answer: the Model Rule alone does not forbid mining, and the result turns on local authority.

The facts that moved the answer were the hidden data and the act of searching for it. Reading a document as it appears is ordinary review and falls outside mining, which is a search of the document's underlying data for hidden or embedded information.²¹ A scrubbed file leaves nothing to mine. The same search by the same lawyer in a state that follows the ABA's view draws no discipline for the search itself, and that permissive position is next.

Mining as Permissible

The permissive view takes the silence of Rule 4.4(b) at face value. The text asks only for prompt notice,²³ and ABA Formal Opinion 06-442 found no provision in the Model Rules that forbids a lawyer to review and use metadata in a file received from opposing counsel. It read Rule 4.4(b) as silent on whether the recipient may do either.²⁴ On that reading the rule requires notice of inadvertently disclosed metadata and sets no other specific restriction on the receiving lawyer's conduct.²⁵ A lawyer in a jurisdiction that follows the ABA who opens a file's revision history therefore breaks no Model Rule merely by looking.

State authorities add a reason drawn from the lawyer's work for the client. The Vermont Bar Association's Ethics Opinion 1 (2009) found “nothing to compel the conclusion that a lawyer who receives an electronic file from opposing counsel would be ethically prohibited from reviewing that file … to expose the file's content, including metadata,” and added that a contrary holding would limit a lawyer's ability to analyze material from opposing counsel diligently and thoroughly.²⁶ Maryland, Oregon, and Wisconsin have adopted similar views.²⁷

The two camps read the same facts differently. The prohibitionist states see a search that intrudes on material the sender never meant to disclose. The ABA and Vermont see a lawyer reviewing a file the other side sent, with nothing in the rules to forbid it.

The ABA opinion's authority is limited, and the limit matters on an exam. ABA formal opinions have no precedential weight, though courts look to them for guidance in interpreting the Model Rules, and a jurisdiction that has not addressed metadata mining generally uses the ABA's advisory opinion as its guide in disciplinary actions.²⁸ That guidance is persuasive and nothing more, so a state with its own contrary opinion governs its own lawyers. Nor can a student assume the ABA's view prevails nationwide, because the jurisdictions that have issued opinions point in opposite directions, and the majority of them forbid mining.²⁹

Permission to look does not end the lawyer's duties, because the notice duty survives it. Rule 4.4(b) still requires prompt notice whenever the lawyer knows or reasonably should know that the document or ESI was inadvertently sent.³⁰ Mining also changes when that knowledge arises. A recipient who never searches may never learn that hidden data exists, while a recipient who searches may find something that announces its own mistake.

Hypothetical Illustration

Mendes practices in a jurisdiction that follows the ABA opinion. Opposing counsel emails a draft settlement agreement as a word-processing file that was never scrubbed. Mendes opens the revision history and finds a margin comment from opposing counsel to the client, stating that the client will pay up to $2.4 million and that the opening position should be $1.8 million. The review violated no Model Rule. The comment is plainly internal advice that no one meant to send, so Mendes reasonably should know it was inadvertently sent, and prompt notice to the sender is now due. What Mendes may do with the figure after giving notice is a separate question for the other law discussed above. A redline that opposing counsel deliberately sent with its tracked changes visible, in order to negotiate against it, carries nothing sent by mistake, so reading it triggers no notice duty.

An exam stem on metadata rewards the answer that begins with the jurisdiction. A student who has just read the prohibitionist states may answer that mining is always unethical, and a student who has just read the ABA opinion may answer that it is always permitted. Both skip the question the stem asks. The same search that draws no discipline under the Vermont opinion violates the ethics rules of North Carolina, whose 2009 Ethics Opinion 1 treats active searching as an interference with the other lawyer's client relationship.³¹ Where the stem names no jurisdiction, the accurate answer is that the Model Rules do not forbid the search, that the ABA's view is persuasive guidance, and that the notice duty still applies if the lawyer knows or reasonably should know the data was inadvertently sent.

Case-by-Case Approaches

Several states reject both absolutes. Rule 4.4(b) still commands prompt notice whenever the knowledge condition is met, but it leaves open whether the recipient may go looking for hidden data.³³ These states' opinions carve out situations in which a lawyer may ethically look at metadata, and each makes the answer depend on something about the particular lawyer, file, or surrounding law.³⁴

West Virginia Legal Ethics Opinion 1 (2009) offers the most concrete example. If a lawyer has received electronic documents and has actual knowledge that metadata was inadvertently sent, the receiving lawyer “should not review the metadata before consulting with the sending lawyer to determine whether the metadata includes work-product or confidences.”³⁵ The restriction has a defined trigger, actual knowledge that the metadata was sent by mistake, and a defined sequence: consultation with the sending lawyer comes before any review. The consultation lets the sending lawyer say whether the hidden comments and tracked changes contain work product or client confidences. Because the trigger is actual knowledge, a recipient with no reason to suspect a mistake falls outside the opinion's terms.

Pennsylvania and Minnesota decline to draw even that much of a line. In 2009 the Pennsylvania Bar Association's Committee on Legal Ethics and Professional Responsibility held that a receiving lawyer's duties with respect to mining metadata must be evaluated on a case-by-case basis “in light of relevant substantive and procedural law.”³⁶ Minnesota Ethics Opinion 22 (2010) likewise suggested that “whether and when a lawyer may be advised to look or not look for … metadata is a fact specific question.”³⁷ The two differ in emphasis. Pennsylvania sends the analysis to substantive and procedural law outside the ethics rules, the same kind of other-law duties noted earlier in this chapter. Minnesota puts the weight on the facts, and its words “whether and when” raise a question of timing as well as permission. Neither opinion, as quoted, fixes the result in advance.

Tying the restriction to what the lawyer knows, as West Virginia does, or to the facts and surrounding law, as Pennsylvania and Minnesota do, keeps two different lawyers from being treated alike. A flat prohibition would treat a lawyer who simply opens a routine file the same as one who knows the comments were left in by mistake. A flat permission would make the same equation from the other side. Hidden metadata never appears unless the receiving lawyer consciously decides to search for it, and the sender may never have known the data existed,³⁸ so knowledge of a mistake is a fact that varies from recipient to recipient.

Hypothetical Illustration

Farrow and Delgado each practice in a jurisdiction that follows the West Virginia opinion. The cover email attached to the draft agreement Farrow receives reads, “Attached is the draft; our internal comments to the client were left in by mistake.” Farrow therefore has actual knowledge that the metadata was inadvertently sent, and he should not review the comments until he has consulted the sending lawyer about whether they contain work product or confidences. Delgado receives a draft from a different firm with no message suggesting anything is amiss, and she has no reason to think any hidden data was left in by mistake. She reads the draft as it appears on the screen, and the restriction does not apply to her because the trigger of actual knowledge is not met.

The cover email moved the answer, because the two lawyers hold the same kind of file in the same state and only Farrow knows that something was sent by mistake. The Model Rule's notice duty runs on its own track in both situations. It arises whenever a lawyer knows or reasonably should know that the item was inadvertently sent, so Farrow owes the sender notice, while Delgado would owe it only if something she later read led a reasonable lawyer to recognize a mistake.³⁹

These three opinions illustrate the middle approach and do not survey every state that has spoken. A metadata question cannot be answered with “mining is unethical” or “mining is permitted.” The answer begins with the jurisdiction, turns next on whether the lawyer knew the transmission was a mistake, and in some states depends on further facts and on law outside the ethics rules.