Analysis by Daniel Burke, CNN Religion Editor

(CNN) -- In July, Pennsylvania Attorney General Josh Shapiro wrote a personal letter to Pope Francis, warning him that "a comprehensive investigation" by his office had found "widespread sexual abuse of children and a systemic coverup by leaders of the Catholic Church."

Shapiro says he never received a response.

The six Pennsylvania dioceses named in the scathing grand jury report received copies of the 800-page document in May, according to Crux News. Before the report was published on Tuesday, Cardinal Donald Wuerl, one of the Pope's top allies and the former bishop of Pittsburgh, had a detailed website prepared to defend himself against charges that he shielded abusive priests. (The website was removed on Thursday after an outcry from Catholics.)

So the idea that the Vatican was caught off guard by the explosive report or needs more time to process it is increasingly difficult to understand -- as is the Pope's silence on the matter. This is a pontiff, after all, who has chastised the media for ignoring the deaths of homeless people.

What's the threshold of victims it would take for the Vatican to quickly respond to the grand jury report? 2,000 children? Or 3,000?

Is 1,000 children abused at the hands of Catholic clergy not enough to warrant a comment from their Holy Father?

Apparently not.

"We have no comment at this time," Paloma Ovejero, deputy director of the Vatican's press office, said on Wednesday. On Thursday, the Vatican again declined to comment.

Meanwhile, in the United States and elsewhere, pressure continues to mount on Pope Francis to address a rapidly escalating crisis that has spread across several continents, from Australia to Latin America.

In the United States, both liberal and conservative Catholics displayed a rare unity in pressing the Pope to respond to the Pennsylvania grand jury report.

"The silence from the Vatican is disturbing," said Massimo Faggioli, a theology professor at Villanova University in Pennsylvania. "I don't think the Pope necessarily has to say something today. He needs time to understand the situation. But someone from the Vatican should say something."

Faggioli noted that Wednesday was a national holiday in Italy, and many church offices were closed. But he also noted that it was well-known that Pennsylvania's grand jury report, which was in the works since 2016, would be released on Tuesday.

"I don't think they understand in Rome that this is not just a continuation of the sexual abuse crisis in the United States," Faggioli said. "This is a whole different chapter. There should be people in Rome telling the Pope this information, but they are not, and that is one of the biggest problems in this pontificate -- and it's getting worse."

Matthew Schmitz, an editor at First Things, a conservative Catholic magazine, said, "Francis has been unfairly attacked at times for his response to clergy sexual abuse. But his response has been disappointing. I hope that enough pressure can be created that he does act to investigate these issues."

Earlier this month, Schmitz was one of several dozen young Catholics who wrote an open letter to Francis, telling him they are angry over yet another case of abuse: the allegations against former Cardinal Theodore McCarrick, former archbishop of Washington and one of the most powerful figures in the American church.

McCarrick, who recently resigned from the church's College of Cardinals, has been accused of molesting young boys and seminarians -- accusations he denies.

Schmitz and other Catholics say that while many priests have been punished for abusing minors, the bishops who covered up the crimes have largely escaped punishment, a point echoed in Tuesday's report from the grand jury in Pennsylvania.

"Priests were raping little boys and girls, and the men of God who were responsible for them not only did nothing; they hid it all," the grand jury said. "For decades. Monsignors, auxiliary bishops, bishops, archbishops, cardinals have mostly been protected; many, including some named in this report, have been promoted."

What can the Pope do?

Under canon law, the rules that govern the Catholic Church, the Pope has the power to remove or otherwise punish bishops.

But canon law is vague about when, exactly, that should be done, church experts said. No concrete crimes or corresponding penalties are listed in canon law, said the Rev. Hans Zollner, a member of the Pontifical Commission for the Protection of Minors and a professor of psychology at the Pontifical Gregorian University in Rome.

What's more, there are some 5,100 bishops around the world, Zollner said, and it would be impractical to expect the Pope to personally monitor every one and investigate every accusation of abuse or negligence.

Other offices within the Vatican have the power to commence investigations, but it is unclear whether they have the power to discipline bishops, Zollner said.

"What is needed is a complete overhaul of that system," Zollner said, "at least in the penal part of the Code of Canon Law."

In response to the McCarrick scandal, top American bishops have proposed subjecting bishops and other high-ranking clergy to oversight from bishops or competent lay leaders.

On Thursday, Cardinal Daniel DiNardo, president of the U.S. Conference of Catholic Bishops, said the bishops have begun to outline a plan that would ask the Vatican to launch a full investigation into McCarrick, make reporting of abuse and misconduct by bishops "easier" and advocate for "better procedures" to resolve complaints against bishops.

"The first criterion is genuine independence," DiNardo said. "Any mechanism for addressing any complaint against a bishop must be free from bias or undue influence by a bishop. Our structures must preclude bishops from deterring complaints against them, from hampering their investigation, or from skewing their resolution."

DiNardo also said that lay people -- not just church clerics -- should be given "substantial involvement."

"Whatever the details may turn out to be regarding Archbishop McCarrick or the many abuses in Pennsylvania (or anywhere else), we already know that one root cause is the failure of episcopal leadership."

Bishops have resigned over sexual abuse cover-ups before.

In the United States, three bishops resigned in 2015 after accusations that they covered up cases of clergy sexual abuse.

After an emergency summit in Rome this May, 31 bishops from Chile offered to resign, an unprecedented action in the modern church, according to a church spokesman. The Pope had called the country's bishops to Rome after he received a 2,300-page report detailing sexual abuses by priests in Chile. The Pope has accepted the resignations of five of the bishops.

After the Pennsylvania grand jury report, none of the bishops named in the report offered to resign. At least, not publicly.

'A playbook for concealing the truth'

Tuesday's grand jury report said internal documents from six Catholic dioceses in Pennsylvania show that more than 300 "predator priests" have been credibly accused of sexually abusing more than 1,000 child victims.

The grand jury described the church's methods as "a playbook for concealing the truth" after FBI agents identified a series of practices they found in diocese files.

The grand jurors said that "almost every instance of abuse we found is too old to be prosecuted." But charges have been filed against two priests, one in Erie diocese and another in Greensburg diocese, who have been accused of abusing minors.

At a news conference announcing the report's release, Pennsylvania Attorney General Josh Shapiro called it the "largest, most comprehensive report into child sexual abuse within the Catholic Church ever produced in the United States."

Although the Vatican declined to comment, DiNardo and Bishop Timothy L. Doherty, chair of the bishops' Committee for the Protection of Children and Young People, issued a statement:

"The report of the Pennsylvania grand jury again illustrates the pain of those who have been victims of the crime of sexual abuse by individual members of our clergy, and by those who shielded abusers and so facilitated an evil that continued for years or even decades," they said.

"As a body of bishops, we are shamed by and sorry for the sins and omissions by Catholic priests and Catholic bishops."

A holy day of obligation

Greg Kandra, a Catholic deacon in Brooklyn, New York, said he awoke on Wednesday to countless fellow Catholics expressing outrage on social media about the Pennsylvania grand jury report.

The presence of social media is a key difference between now and 2002, when a wave of sexual abuse scandals rocked the Catholic Church, beginning in Boston and quickly spreading to dioceses across the United States.

"What we have now is people freely expressing their outrage on Facebook and Twitter," Kandra said, "and that is where this story is starting to take off. The anger is palpable. This is like 2002 on steroids."

Another difference between now and 2002, Kandra said, is the focus on bishops -- not just priests -- and the accusations that they covered up for abusive priests or even engaged in abuse themselves.

"There has to be some accountability for the people in upper management in the church," Kandra said. "That isn't really happening right now. Bishops need to be accountable not only to the Pope and to their fellow bishops, but also to the people they serve."

Wednesday marked the Feast of the Assumption in the Catholic Church, a holy day of obligation that recalls the Virgin Mary's ascent into heaven, and Kandra was one of about 500 Catholics who attended noon Mass at a church in Brooklyn. The priest who celebrated the Mass didn't mention the abuse scandal. At least, not directly, Kandra said.

"He preached about evil and turning to the Blessed Mother to protect us. But he didn't address the big news (about the grand jury report). Maybe he's waiting until Sunday."