The students belonging to the Network for Self-Education said the reason for the occupation was "...the rector has not yet given instructions for free access during the visit of Benedict XVI. We believe that it is not acceptable that they should close the entire area of the university - an actual red zone not allowing students to gain access to their faculty."
The controversy began after 67 professors at the university signed a letter saying the pope should not be allowed to give the inauguration speech for the academic year. The signatories include distinguished physicists such as Andrea Frova, author of a study of Galileo's persecution by the Church, and Carlo Maiani, the recently appointed head of the Italian National Council for Research.
The letter said scientists felt "offended and humiliated" by a statement made in 1990 by the then Cardinal Joseph Ratzinger as Prefect of the Congregation for the Doctrine of the Faith - the modern descendant of the Inquisition - suggesting that the trial of Galileo for heresy because of his support for the Copernican system was justified in the context of the time.
The scientists said they hoped the visit by the Pope on Thursday would be cancelled out of respect for the "secular nature of science" and the fact that the university was open to "students of every belief and ideology".
On Monday student protesters at the university began a planned four days of demonstrations. A variety of outside groups, including labor unions and the Italian Movement of Transsexuals, had also planned to protest Benedict’s appearance on Thursday.
PR Inside.com reports banners have been strung from university buildings and posters plastered on walls objecting to the visit. «Science is secular,» read one banner hanging from the geology department building. «No pope» read another slogan on a poster.
What about those safety fears?
Students had threatened to blast dance music at the pontiff, and also to dress up as nuns. Pretty scary stuff.
But then as a cardinal, Benedict once attacked rock and pop music as the "work of the devil."
And nuns, well, what Pontiff wouldn't be afraid?
The following is from the Euro News.
Pope pulls out of university visit after protests
The Vatican has cancelled a planned visit by Pope Benedict to Rome's most prestigious university, following protests by students and staff.
It is an unprecedented move since the former Cardinal Joseph Ratzinger took over the Roman Catholic Church in April, 2005.
He was due to speak at La Sapienza University on Thursday at a ceremony launching the 2008 academic year.
But, defending higher education as secular, some there demanded his invitation be withdrawn.
Students occupied the offices of the chancellor as more than 60 professors wrote to the university, saying they were offended and humiliated by some of the Pope's views.
Critics claim that in a speech he gave nearly twenty years ago, the Pontiff condoned the Church's heresy trial against the astronomer Galileo.
Professor Marcello Cini has been at the forefront of the protest.
"We are getting a bit too close to those states in which citizens are given orders about what to do by a religious authority," he said.
Protesters are in a minority at the university, But feelings on both sides are strong.
One student argued the institution was secular.
"The Pope has nothing to say to us," he said.
But another wondered whether a visit from a Rabbi or an Imam would have triggered the same reaction. She said there was no harm because the Pope would have been speaking in a church, not a law class, and what is more, he was invited.