On a forum I frequent, someone asked it the thrower was excommunicated, since Canon Law provides that
Can. 1370 §1. A person who uses physical force against the Roman Pontiff incurs a latae sententiae excommunication reserved to the Apostolic See; if he is a cleric, another penalty, not excluding dismissal from the clerical state, can be added according to the gravity of the delict.'Latae sententiae', means that excommunication is automatic, needing no judicial verdict for it take effect.
A friend posted this reply to the question,
Only if they intended and caused physical harm to the Pope.
For instance if you happened to, in devotion to His Holiness toss a copy of the Summa as a gift at him as he passed, and hit him in the head, it wouldn't be an excommunication. You were acting out of devotion and love, perhaps a bit misguided, but you weren't trying to hurt him.
Along those lines, perhaps someone will want to gift him with a copy of the Catechism of the Councii of Trent or a Denziger . I suspect he may not have access to a copy. In fact it seems like the library copy might last have been borrowed by Pius XII, and he must have misplaced it before he died.For those who are not familiar with the two works cited, the Catechism of the Council of Trent, or Roman Catechism, is the official exposition of the Catholic Faith, ordered by the Œcumenical Council of Trent, and probably still the best explanation of the Faith available. Denziger, or the Enchiridion symbolorum, definitionum et declarationum de rebus fidei et morum, (Handbook of creeds, definitions, and declarations on matters of faith and morals) is a compendium of all the basic texts on Catholic dogma and morality since the Apostolic Age. Commissioned by Blessed Pope Pius IX, it has been in use since 1854, and has been regularly updated since.
My friend is implying the obvious, that Popes since Pius XII, and especially Francis, have forgotten the basics of Catholic doctrine.