9 But their profession of fidelity to the Vicar of Christ is vain in those who, in fact, do not cease to violate the authority of their Bishops. For "by far the most august part of the Church consists of the Bishops, (as Our Predecessor Leo XIII of holy memory wrote in his letter of December 17, 1888, to the Archbishop), inasmuch as this part by divine right teaches and rules men; hence, whoever resists them or pertinaciously refuses obedience to them puts himself apart from the Church. . . On the other hand, to pass judgment upon or to rebuke the acts of Bishops does not at all belong to private individuals - that comes within the province only of those higher than they in authority and especially of the Sovereign Pontiff, for to him Christ entrusted the charge of feeding not only His lambs, but His sheep throughout the world. At most, it is allowed in matters of grave complaint to refer the whole case to the Roman Pontiff, and this with prudence and moderation as zeal for the common good requires, not clamorously or abusively, for in this way dissensions and hostilities are bred, or certainly increased."
Source: Tribus Circiter (Vatican.va)