Jennifer Dickey Jennifer Dickey
Vice President and Deputy Chief Counsel, U.S. Chamber Litigation Center


December 14, 2022


We are seeing a resurgence of demands for “injunctive” relief under Rule 23(b)(2) class actions that can only be described as astonishing. Some would require companies to undertake actions that would cost billions of dollars to complete; others are so ill-defined that it is hard to know what would even constitute compliance. In a recent blog post, I flagged an important question for businesses seeking to counteract this surge: what limits, if any, are there on the injunctive remedies that may be available for classes certified under Rule 23(b)(2)? That provision allows certification of a class when “the party opposing the class has acted or refused to act on grounds that apply generally to the class, so that final injunctive relief or corresponding declaratory relief is appropriate respecting the class as a whole.”1 And this post provides the beginnings of an answer to that question.

I. Limits on Rule 23(b)(2) Class Actions Recognized by the Supreme Court and Advisory Committee

The Supreme Court has identified certain basic limits on the relief available under Rule 23(b)(2). For example, as should be evident from its text, claims for monetary relief may not be certified under Rule 23(b)(2), at least where “the monetary relief is not incidental to the injunctive or declaratory relief.” 2 Indeed, the Supreme Court has indicated that it is possible that the provision “does not authorize the class certification of monetary claims at all.”3 Moreover, Rule 23(b)(2) certification “applies only when a single injunction or declaratory judgment would provide relief to each member of the class” and “does not authorize class certification when each individual class member would be entitled to a different injunction or declaratory judgment against the defendant” nor “when each class member would be entitled to an individualized award of monetary damages.”4

These interpretations are largely consistent with the advisory notes, which express the view that Rule 23(b)(2) “does not extend to cases in which the appropriate final relief relates exclusively or predominantly to money damages.”5 Those notes identify several “[i]llustrative” examples of actions they viewed as proper under the new Rule 23(b)(2). These include the “various actions in the civil-rights field where a party is charged with discriminating unlawfully against a class, usually one whose members are incapable of specific enumeration,” such as the desegregation cases involving schools and places of public accommodation.6 The notes also mention, as examples of an appropriate suit under this provision, a class of retailers who bring suit against a seller who is alleged to have sold to them at higher prices than other retailers “when the applicable law forbids such a pricing differential,” and a patentee who sues to challenge a tying condition on the sale or licensing of a machine.7

But it sometimes seems that there are fewer things in heaven and earth than are dreamt of by class-action lawyers crafting a plea for relief.8 Indeed, the Sixth Circuit recently agreed to hear an interlocutory appeal from a class certification decision where the plaintiffs are seeking “an injunction ordering the defendants to fund a ‘science panel’ to study the effects of [per- and polyfluoroalkyl substances (“PFAS”)]—whether and to what it extent it may increase the risk of disease—and potentially to provide medical monitoring for every member of the class,” which “comprises nearly all 11.8 million residents of Ohio, along with anyone else otherwise subject to its laws.”9 As the Sixth Circuit noted, “[t]hough the relief plaintiffs seek purports to be an ‘injunction,’ it would have the practical effect of extracting billions of dollars from defendants.”10 That case is not alone.11

II. Three Limits on Rule 23(b)(2) Class Actions from Equitable Practice

The question thus becomes what, if any, limits there are on the “final injunctive relief or corresponding declaratory relief” that is “appropriate” and thus available under the Rule? The Supreme Court has noted that “Rule 23 ‘stems from equity practice’ that predated its codification” and accordingly that “in determining its meaning we have previously looked to the historical models on which the Rule was based.”12 A look at equity practice reveals a number of potential limits on class actions under this provision. This blog post focuses on just three.

First, at a minimum, equity practice suggests that courts should be skeptical of requests under Rule 23(b)(2) for mandatory injunctions compelling affirmative steps by the defendant. It is very clear that, at the founding, and for a long time thereafter, injunctions were understood as primarily prohibitory in nature, restraining a party from doing something, not compelling that party to do anything.13 For example, according to one early 19th century source, prohibitory injunctions might “stay proceedings” in other courts; “restrain the indorsement or negotiation of notes and bills of exchange, the sale of land, the sailing of a ship, the transfer of stock, or the alienation of a specific chattel”; or “prevent the wasting of assets or other property pending litigation.”14 They might also “restrain the commission of every species of waste to houses, nines, timber, or any other part of the inheritance”; “prevent the infringement of patents, and the violation of copyright either by publication or theatrical representation”; “suppress the continuance of public or private nuisances”; or “stop the progress of vexatious litigation.”15

Mandatory injunctions, if not verboten, were viewed as the most exceptional of the exceptional injunctive remedies.16

Consistent with that history, all of the 1966 advisory notes’ examples are prohibitory in nature, though those notes do contemplate the possibility of mandatory injunctions when discussing how relief to one member of a class might affect others and thus necessitate class treatment under Rule 23(b)(1).17

That mandatory injunctions should be disfavored might seem like a formalism, given that the distinction “between prevention, ‘or prohibition,’ and command, in reference to injunction,” has sometimes been viewed as “rather nominal than substantial.”18 For example, an injunction nominally prohibiting someone from continuing to plug up a stream of water would effectively require affirmatively removing the plug that one had placed.19 But the restriction wasviewed as meaningful, reflecting the reality that a court’s equitable powers were not viewed as authorizing any court order that the judge might deem beneficial.

Indeed, as Justice Story explained at length in his commentaries on Equity Jurisprudence, if equitable powers were unbounded, they would become “the most formidable instrument of arbitrary power, that could well be devised.”20 Indeed, if it were so, equity would “well deserve the spirited rebuke of Selden,” who memorably (and critically) analogized equity to what would happen if we tried to make the standard measurement a Chancellor’s foot: One Chancellor has a long foot, another a short foot, and a third an indifferent foot. “It is the same thing with the Chancellor’s conscience.”21

Thus, while the U.S. Supreme Court has not viewed a mandatory injunction as completely beyond the powers of a court of equity, it has cautioned that it should be used only “where the circumstances of the case demand it.”22 Moreover, the Supreme Court has noted that “[a] mandatory injunction, like mandamus, is an extraordinary remedial process, which is granted, not as a matter of right, but in the exercise of a sound judicial discretion.”23

In terms of the circumstances that might make a mandatory injunction appropriate, perhaps the most common set of circumstances described in equitable treatises involved property rights. Specifically, “[w]here there [wa]s a deliberate, unlawful, and inexcusable invasion by one man of another’s land for the purpose of continuing trespass for the trespasser’s gain or profit, and there ha[d] been neither acquiescence nor delay in applying to this court for relief,” courts of equity would issue “a mandatory injunction against the continuance of the trespass,” which may have involved, for example, taking down a wall or other matter that trespassed on the property rights.24 Even if phrased as prohibitory in form (“Don’t continue to trespass”), it would be mandatory in effect because it compel the performance of certain affirmative acts.

Second, injunctions were understood as “a preventative remedy.” “If the injury be already done, the writ can have no operation, for it cannot be applied correctively so as to remove it. It is not used for the purpose of punishment or to compel persons to do right, but simply to prevent them from doing wrong.”25 This makes sense, as one ordinarily thinks of damages as a remedy for a harm that has already been completed. In the case of the mandatory injunction above, for example, a trespass has already begun but is also ongoing based on the presence of the wall on the other person’s land. The injunction addresses the latter.

There may exist a great deal of overlap between this limit on equitable relief and the Article III standing limits on those seeking declaratory or injunctive relief.26 The Supreme Court has held that a plaintiff seeking declaratory or injunctive relief must show that he is sustaining or “is immediately in danger of sustaining some direct injury” from the challenged conduct and that the injury is “real and immediate,” not “conjectural” or “hypothetical.”27 A past injury might be sufficient to ground a claim for damages, but not a claim for declaratory or injunctive relief.28

But the overlap does not mean this limit lacks force. It may be, for example, that a particular plaintiff possesses standing to seek some sort of declaratory or injunctive relief but the particular relief the plaintiff seeks would not be preventative and thus not appropriate under Rule 23(b)(2). Denial of certification on this basis should follow. Courts are also currently split about whether unnamed class members need to establish Article III standing at the class certification stage, but even if a case presented itself with named plaintiffs who had standing and unnamed class members who might not, class certification under Rule 23(b)(2) would be inappropriate if the injunction sought is not a preventative remedy. Keeping this limit in mind may help ferret out requests for certification under Rule 23(b)(2) that are nothing but an end-run around the limits on damages class actions in Rule 23(b)(3).

Third, it has been said that “[c]ourts of equity w[ould] decline to exercise jurisdiction by injunction where the questions involved [we]re wholly new and [we]re so broad and deep and difficult that they cannot be measured by existing modes of equitable relief.”29 The theory was that the matter was “legislative rather than judicial and [wa]s to be treated as affecting the public as well as individuals.”30

While it is unclear from the treatises how common it was for courts of equity to encounter such circumstances, more modern case law continues to support this rule.31 As the Supreme Court said less than two decades ago, “it has long been established that a federal court has the authority to decline to exercise its jurisdiction when it is asked to employ its historic powers as a court of equity.”32 Indeed, “[t]he history of equity jurisdiction is the history of regard for public consequences in employing the extraordinary remedy of the injunction.”33 Thus, the Supreme Court has reiterated that courts have the discretion, in appropriate circumstances, to not only stay an action but to outright dismiss it.34 And because discretion is not unbounded, it seems likely that there are at least some putative 23(b)(2) class actions that would warrant dismissal purely on this basis.

* * *

A rule 23(b)(2) injunctive class may be the proverbial wolf in sheep’s clothing. Without the hefty dollar figure explicitly attached to its claims,35 a request for a class-wide injunction may seem almost benign. But recent practice proves otherwise. The equitable principles outlined in this blog post are just the tip of the iceberg for limits on the federal courts’ exercise of equitable powers that may be able to sink abusive 23(b)(2) class actions. Time for businesses (and practitioners) to plumb those depths.

1 Fed. R. Civ. P. 23(b)(2).

2 Wal-Mart Stores, Inc. v. Dukes, 564 U.S. 338, 360 (2011).



5Advisory Committee Notes on the 1967 revision.



8 With apologies to William Shakespeare, Hamlet, Act 1, scene 5.

9In re 3M Co., No. 22-0305, 1-2 (6th Cir. Sept. 9, 2022).

10Id. at 17.

11See, e.g., Wit v. United Behavioral Health, 2022 WL 850647 (9th Cir. 2022) (reversing on other grounds a Rule 23(b)(2) class certification order that would have required “reprocessing” of 67,000 benefits coverage determinations that would have cost more than $30 million to conduct).

12Wal-Mart Stores, Inc., 564 U.S. at 361.

13 “An injunction is defined as ‘a prohibitory writ, specially prayed for by a bill in which the plaintiff’s title is set forth, restraining a person from committing or doing an act (other than criminal acts)(a) which appears to be against equity and conscience.’” Francis Hilliard, The Law of Injunctions § 1 (2d ed. 1869) (quoting Bouv. Law Dict.; Whart. Law Dict.); William Joyce, I The Law and Practice of Injunctions in Equity and at Common Law, intr. (1872) (“An injunction is a writ remedial, issuing by the order of a Court of Equity, in those cases where the plaintiff is entitled to equitable relief, by restraining the commission or continuance of some act of the defendant.”); see also Development in the Law-Injunction, 78 Harv. L. Rev. 1055, 1061 (1965) (“American courts have frequently stated that a stronger showing is required to obtain a mandatory decree, although courts denying such decrees have tended to base their refusal upon a general want of equity rather than upon any explicit comparison with the requirements for a prohibitory injunction. Courts have also demonstrated a proclivity to frame all decrees in negative language.”).

14 Hon. Robert Henley Eden, A Treatise on the Law of Injunctions 1-2 (1821).


16 Hilliard, supra, § 6a (“[A]mandatory injunction may be granted, where the injury has been completed before the filing of the bill, whether in case of easements or other rights. Though it will be done only to prevent extreme or very serious damage.”); James L. High, A Treatise on the Law of Injunctions § 2 (1879) (“While the jurisdiction of equity by way of mandatory injunction is rarely exercised and while its existence has even been questioned, it is nevertheless too firmly established to admit of doubt…It is to be observed, however, that courts of equity rarely interfere to compel the doing of a positive act, but the same result is obtained by framing the injunction in an indirect form and prohibiting the defendant from doing the reverse of what he is desired to do. Even then the jurisdiction is exercised with extreme caution, and is confined to cases where the courts of law are unable to afford adequate redress, or where the injury can not be compensated in damages.”). Although a deep dive into the equity case law at the time of the Founding is beyond the scope of this blog post, businesses interested in making this argument should consider commissioning such research because it is possible that these readily-available treatises may even gloss over some relaxation of remedial requirements between the time of the Founding and their publication, a relaxation that would not apply to the federal courts.

17Notes of Advisory Committee on Rules – 1966 Amendment to Rule 23 (“A negative or mandatory injunction secured by one of a numerous class may disable the opposing party from performing claimed duties toward the other members of the class or materially affect his ability to do so.”).

18 Hilliard, supra, § 6a.

19 Jacob Klein, 12 Harv. L. Rev. 95, 99 (1898) (describing the circumstances of Filley v. Bambrick, No. 92,462 (Cir. Ct. St. Louis 1895).

20 Joseph Story, I Commentaries on Equity Jurisprudence §19 (4th ed. 1846).

21Id. (quoting Selden’s Table Talk, title Equity; 3 Black. Comm. 432, note (y)).

22Ex parte Lennon, 166 U.S. 548, 556 (1897).

23Morrison v. Work, 266 U.S. 481, 490 (1925) (declining to issue a mandatory injunction).

24Broome v. New York & New Jersey Telephone Co., 7 A. 851, 852 (N.J. Ct. Chancery 1887).

25 Hilliard, supra, § 5; see also John Norton Pomeroy Jr., 1 A Treatise on Equitable Remedies, Supplementary to Pomeroy’s Equity Jurisprudence § 3 (1905).

26 SeeCity of Los Angeles v. Lyons, 461 U.S. 95, 105 (1983) (“If Lyons has made no showing that he is realistically threatened by a repetition of his experience of October, 1976, then he has not met the requirements for seeking an injunction in a federal court, whether the injunction contemplates intrusive structural relief or the cessation of a discrete practice.”).

27Id. at 102.

28Id. at 105.

29 Charles Fisk Beach Jr., I Modern Equity: Commentaries on the Law of Injunctions § 48 (1895).


31Quackenbush v. Allstate Ins. Co., 517 U.S. 706, 717 (1996).


33Id. (quoting Railroad Comm’n of Tex. v. Pullman Co., 312 U.S. 496, 500 (1941). 721.

35 See Wal-Mart Stores, Inc., 564 U.S. at 360.

About the authors

Jennifer Dickey

Jennifer Dickey

Jennifer B. Dickey is vice president and deputy chief counsel at the U.S. Chamber Litigation Center, the litigation arm of the U.S. Chamber of Commerce. Dickey handles a variety of litigation matters for the Chamber.

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