What's interesting is that the the decree Mr. Bellisario cuts and pastes from here (link) makes reference to an earlier bull, Exsurge Domine, also by Leo X, in which Leo X says:
Moreover, because the preceding errors and many others are contained in the books or writings of Martin Luther, we likewise condemn, reprobate, and reject completely the books and all the writings and sermons of the said Martin, whether in Latin or any other language, containing the said errors or any one of them; and we wish them to be regarded as utterly condemned, reprobated, and rejected. We forbid each and every one of the faithful of either sex, in virtue of holy obedience and under the above penalties to be incurred automatically, to read, assert, preach, praise, print, publish, or defend them. They will incur these penalties if they presume to uphold them in any way, personally or through another or others, directly or indirectly, tacitly or explicitly, publicly or occultly, either in their own homes or in other public or private places. Indeed immediately after the publication of this letter these works, wherever they may be, shall be sought out carefully by the ordinaries and others [ecclesiastics and regulars], and under each and every one of the above penalties shall be burned publicly and solemnly in the presence of the clerics and people.
Indeed, the bull pasted by Bellisario makes reference to this particular section, noting: "in several states and localities of the said Germany the books and writings of the said Martin were publicly burned, as we had enjoined."
The document concludes (in a style normal for papal bulls): "X No one whatsoever may infringe this our written decision, declaration, precept, injunction, assignation, will, decree; or rashly contravene it. Should anyone dare to attempt such a thing, let him know that he will incur the wrath of Almighty God and of the blessed Apostles Peter and Paul."
I've asked before, and I'll ask again: who has infringed this written decision and/or contravened it? Did they do so with a greater authority than that of Leo X?
I've heard people claim that "canon law" has done away with the penalty announced by Leo X for reading Luther, but I have not seen how they propose to use canon law to overcome, infringe, or contravene a papal bull.