When the Catholic Church introduced the official Traditional Latin Mass in 1570, they sent out a decree ahead of it, warning everyone what was coming. Here's just part of their "warning":
"But in order that what has been handed down by the most holy Roman Church, the Mother and Teacher of the rest of the churches, may be accepted and observed by all everywhere, We forbid [translation of We] that henceforth for all future times in all the patriarchal [churches] of the provinces of the entire Christian world, in all cathedrals, in all secular collegiate and parish churches, and in the churches of any orders, in the churches of monasteries of both men and women, and also regulars of military orders, and both chapels and churches without any care of souls, in which the conventual Mass is sung aloud with the choir or is said silently and is said regularly or is required to be said according to the rite of the Roman Church, [We forbid] that Mass be sung or recited in any other way than according to the formula of the Missal issued by Us; [this prohibition holds] even though these churches are exempt in any way whatever, whether by an apostolic indult, by custom, by privilege, also [if exempt] by oath, by apostolic confirmation or if they are protected by other faculties of any kind whatesoever; unless [this faculty or exemption] was approved by the Apostolic See from the very beginning of the institution, either by custom, or which very institution of celebrating Mass has been faithfully observed in the same churches for more than two hundred years; from these We in no way, by no means, take away the constitution or custom of celebrating as in the above-mentioned constitution. We make this provision so that if this Missal which We have had issued should please these more, they could with the consent of the Bishop, or of their Prelate, or of a General Chapter, all things to the contrary notwithstanding, celebrate Mass according to this Missal; this We permit. But from all other churches above mentioned We remove [condemn] the use of their Missals, and wholly and entirely reject them, and We decree under penalty of Our indignation that never at any time is anything to be added, subtracted or changed; this We determine and ordain to hold in perpetuity by virtue of this constitution. We strictly command, and We issue this command by virtue of holy obedience, that they set aside wholly and entirely in the future all other observances [rationibus] and rites and Missals, no matter how ancient they may be that they have been accustomed to use, that they reject them entirely, and that they sing and read Mass according to the rite, the mode and the norm of this Missal which is now being issued by Us; and let them not presume to add or recite other ceremonies and prayers in the celebration of Mass than those that are contained in this Missal.
"And in perpetuity We grant and permit that they may by all means use this Missal in singing or reciting Mass in any church whatsoever without any scruple of conscience, without incurring any penalties, sentences, or censures; in order that they may be able to do this and be able to use this Missal freely and lawfully, We by virtue of Our Apostolic Office, and by virtue of this present document, We grant and permit this forever.
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"No one is allowed to go contrary to this letter [paginam] which expresses Our permission, statute, regulation, mandate, precept, grant, indult declaration, or will and Our decree and prohibition; no one is allowed to act against it with rashness or temerity. But if anyone would presume to attempt this, let him know that he will incur the wrath [indignation] of Almighty God and of Saints Peter and Paul, His Apostles."