Maybe she was mad he held midnight mass 2 hours early:
A crazed woman jumped a barrier and rushed at Pope Benedict XVI as he made his way up the aisle at the Vatican to perform the traditional Christmas Eve Mass.
The woman was caught by security guards before she could reach the 82-year-old Pope, who was untouched and barely broke stride. […]
The unidentified woman was arrested by the Vatican’s Swiss Guards. Italian media reports said she was mentally ill.
Or maybe she was angry that the pope has moved Pope Pius XII one step closer to sainthood:
Benedict confirmed the “heroic virtues” of Pius — along with those of John Paul II — on Saturday, opening the door to beatification once a miracle is attributed to each. A second miracle would be required for sainthood.
The move created anger among many Jewish groups, which have argued that Pius did not speak out vocally enough against the Nazis or intervene to save Jews during World War II, and that the Vatican helped many former Nazis escape to South America after World War II.