29 U.S.C. § 107 (LABOR)
§ 107. Issuance of injunctions in labor disputes; hearing; findings of court; notice to affected persons; temporary restraining order; undertakings
No court of the United States shall have jurisdiction to issue a temporary or permanent injunction in any case involving or growing out of a labor dispute, as defined in this chapter, except after hearing the testimony of witnesses in open court (with opportunity for cross-examination) in support of the allegations of a complaint made under oath, and testimony in opposition thereto, if offered, and except after findings of fact by the court, to the effect—
(a) That unlawful acts have been threatened and will be committed unless restrained or have been committed and will be continued unless restrained, but no injunction or temporary restraining order shall be issued on account of any threat or unlawful act excepting against the person or persons, association, or organization making the threat or committing the unlawful act or actually authorizing or ratifying the same after actual knowledge thereof;
(b) That substantial and irreparable injury to complainant’s property will follow;
(c) That as to each item of relief granted greater injury will be inflicted upon complainant by the denial of relief than will be inflicted upon defendants by the granting of relief;
(d) That complainant has no adequate remedy at law; and
(e) That the public officers charged with the duty to protect complainant’s property are unable or unwilling to furnish adequate protection.
Such hearing shall be held after due and personal notice thereof has been given, in such manner as the court shall direct, to all known persons against whom relief is sought, and also to the chief of those public officials of the county and city within which the unlawful acts have been threatened or committed charged with the duty to protect complainant’s property: Provided, however, That if a complainant shall also allege that, unless a temporary restraining order shall be issued without notice, a substantial and irreparable injury to complainant’s property will be unavoidable, such a temporary restraining order may be issued upon testimony under oath, sufficient, if sustained, to justify the court in issuing a temporary injunction upon a hearing after notice. Such a temporary restraining order shall be effective for no longer than five days and shall become void at the expiration of said five days. No temporary restraining order or temporary injunction shall be issued except on condition that complainant shall first file an undertaking with adequate security in an amount to be fixed by the court sufficient to recompense those enjoined for any loss, expense, or damage caused by the improvident or erroneous issuance of such order or injunction, including all reasonable costs (together with a reasonable attorney’s fee) and expense of defense against the order or against the granting of any injunctive relief sought in the same proceeding and subsequently denied by the court.
The undertaking mentioned in this section shall be understood to signify an agreement entered into by the complainant and the surety upon which a decree may be rendered in the same suit or proceeding against said complainant and surety, upon a hearing to assess damages of which hearing complainant and surety shall have reasonable notice, the said complainant and surety submitting themselves to the jurisdiction of the court for that purpose. But nothing in this section contained shall deprive any party having a claim or cause of action under or upon such undertaking from electing to pursue his ordinary remedy by suit at law or in equity.
(Mar. 23, 1932, ch. 90, § 7, 47 Stat. 71.)