A comprehensive view of equity jurisdiction can best be obtained by an examination of the various forms of relief afforded by courts of equity with reference to the kind of relief grant ed. Equity jurisdiction, with reference to the form of relief, may be roughly classified as (a) preventive and (b) remedial.
Courts of equity most frequently exercise their jurisdiction: to prevent threatened injuries to property or analogous interests by means of an injunctive decree or order commanding the de fendant to refrain from committing the threat ened injury, or commanding him to do some act which would prevent the injury. The most com mon forms in which preventive jurisdiction is exercised are: (I) Bills to restrain the commis sion of tort; (2) bills of peace; (3) bills of interpleader; (4) bills quia thud (L., 'because he fears')—in all of which the common ground for exercising jurisdiction is the prevention of threatened injury to the plaintiff, for whom there is no adequate legal remedy.
(1) Bills to Restrain the Commission of a Tort.—As a general rule, equity will restrain the commission of any tort which would result in injury to property and for which legal damages would not be an adequate remedy. Inadequacy may come either because the damage is irrepar able—that is, the property could not be repaired or replaced by the sum received as damages; as, for example, injuries to growing trees, or to a work of art, or to one's business; or the in adequacy may arise from the fact that the de fendant (in equity) threatens to repeat a tort so frequently that the plaintiff will be compelled to resort frequently to a court of law to recover damages, in which ease equity will restrain the commission of the tort upon the principle of a bill of peace. Thus equity will restrain the de fendant from trespassing repeatedly on the plain tiff's land, although legal damages for a single trespass would be adequate. Upon the principle of preventing irreparable injury to a property interest, equity will enjoin the publication of a trade secret belonging to the plaintiff, or of a private letter written by him.
There is also some authority for the view that equity will recognize a right of privacy in a private individual, and will restrain an illegal invasion of that right. The law on this point is, however, still unsettled. Equity will not restrain a libel or slander, or the commission of a crime as such, though the mere fact that a threatened injury to property is also a crime will not pre vent the exercise of equity jurisdiction. This
selflimitation of jurisdiction is somewhat arbi trary, and in England and in most States courts of equity now have statutory jurisdiction to re strain the publication of trade libels.
(2) Bills of Peace.—The object of bills of peace is to relieve the plaintiff from the burden of liti gating a multiplicity of suits, either in law or equity. Thus when one is compelled to bring or defend numerous actions at law or in equity in order to establish his right, a court of equity may issue an injunction restraining alt the sepa rate actions at law- or in equity, and compelling the parties to try them all in equity in a single proceeding; or it may enjoin all the actions at law but a single one, and upon its conclusion adjust the rights of all parties in accordance with the result so obtained. The same relief may he obtained by the several plaintiffs or de fondants in numerous actions at law or in equity, may unite in asking it.
(3) Bills of Intcrpleader.—The object of the bill of interpleader is to release the plaintiff from the demands of numerous parties all claiming of him payment of the same debt or performance of the same obligation. lie is in the position of a stakeholder who is willing to pay over a sum of money to the proper pa rty. but is unable to de• termine who is the proper party. Thus, payment is demanded of A (the maker of a promissory note) by both ii and CI, who claim to be owners of the note. Upon A's offering to pay the money into court and disclaiming any interest therein, equity will enjoin 11 and C' from pro ceeding against A, and compel them to litigate the question of ownership of the note in equity.
(4) Bills Quia Timet.—The object of the bill (Julia time!' is to compel the surrender and can cellation of an instrument, upon which, although invalid, the holder might at some future time found an action at law or in equity against the plaintiff. The relief is granted upon the theory that through lapse of time the plaintiff (in equity) might lose the evidence of the invalidity of the instrument, and thus be subjected to an action after his defense to it is lost. This form of equity jurisdiction is clearly related to bills to remove cloud or title.