A U.S. lawyer for the Vatican argues that, like any former head of state, Benedict retains legal immunity regardless of whether he is in or out of office.
But advocates for victims say immunity in this case should be tested, since modern-day courts have never before dealt with an emeritus pope.
"So much of this is unprecedented," said Pamela Spees, an attorney with the Center for Constitutional Rights in New York, which is pressing the International Criminal Court to investigate the Vatican's response to abusive priests as a crime against humanity. "There's nothing set in stone about it."
Benedict stepped down, becoming the first pontiff in six centuries to do so.
Before he became head of the Roman Catholic Church in 2005, he spent more than two decades in charge of the Congregation for the Doctrine of the Faith, the Vatican office that over the years gained authority to oversee abuse claims against clergy worldwide.
Still, his record on trying to end abuse stands above that of many other church officials.
He instructed the Rev. Marcial Maciel, founder of the conservative Legion of Christ religious order, who was favored by Pope John Paul II, to leave the ministry and lead a life of prayer and penance. Maciel had been accused for years of abusing young men.
Benedict also ordered bishops worldwide to craft guidelines on protecting children and keeping abusers out of the priesthood. Jeffrey Lena, a U.S. attorney for the Vatican, said that Benedict deserves "tremendous credit" for "recognizing the problem and helping to change the church's approach."
However, advocates for victims have criticized his reforms as half-steps.
As evidence, they point to the Maciel case. The pope never disclosed what the influential priest had done wrong. Only later was it confirmed that Maciel had molested seminarians and fathered at least three children.
In Ireland, where church leaders had shielded guilty clerics from prosecution for decades, the Vatican during Benedict's pontificate refused or ignored repeated requests from state investigators for access to its case files.
Benedict's lengthy record dealing with the scandal before he was pope plays a part in the complaint against the church with the International Criminal Court. The court prosecutor, who can decide whether to open an inquiry, has not said whether he will act. Lena has called the effort, which was first filed in 2011, "ludicrous."
Spees said Benedict's resignation would play no role in the longshot case before the International Criminal Court. The world's only permanent war crimes tribunal, its prosecutor does not take into account traditional immunity claims.
However, she and others argue that at a minimum Benedict's resignation could help reduce resistance by prosecutors or other officials to take action against him.
Advocates point to how attitudes changed in the United States, where police and prosecutors once allowed local church officials to deal privately with priests' misconduct. After thousands of civil lawsuits revealed the scope of the abuse scandal, some American civil authorities began aggressively investigating whether Catholic leaders did enough to protect children.
And in staunchly Catholic Ireland, revelations by state investigators about abuse there led to an unprecedented dressing down of the Vatican in 2011 by Prime Minister Enda Kenny.
"They reframed the question," said Timothy Lytton, an Albany Law School professor and author of the book "Holding Bishops Accountable: How Lawsuits Helped the Catholic Church Confront Clergy Sex Abuse."
"Before 1984, nobody talked about it. Police wouldn't investigate it. Now, books are being written on the responsibility of the pope. All over Europe there are questions about the Vatican's role in all this and that is largely the results of lawsuits," he said.
Still, no lawsuit against the Vatican has come anywhere near a trial stage, and it's unclear whether Benedict will now be any easier to reach.
Of the thousands of abuse lawsuits filed against church officials, only a small number have named the Vatican as a defendant. They have come mostly from the United States, with a few from Ireland.
In 2005, just months after the conclave that elected Benedict, a U.S. judge in Texas dismissed a lawsuit, ruling the pope had immunity as a head of state.
The U.S. Justice Department had filed a motion arguing that allowing the suit to proceed would be "incompatible with the United States' foreign policy interests."
Many other lawsuits never got off the ground for a more mundane reason: No suit can proceed until the targeted person is officially notified.
Notes Lytton: "You can't hire a county sheriff to fly to Rome to knock on a door."
Jeff Anderson, a Minnesota attorney who has represented thousands of clergy abuse victims over three decades, including in lawsuits against the Vatican, said in one case the Holy See returned the notification he sent stamped, "Do Not Want. Not Welcome."
Anderson says the lawsuits he has filed target the office of the papacy, not the man who served in it, so Benedict's resignation has no significance for any future U.S. civil suits.
Where the pope's novel status as a retiree could come into play, Anderson says, is if a government decides to take action against him.
Benedict has said he will retreat to a life of prayer in a monastery behind Vatican walls, leading victims groups to wonder whether preserving the former pope's legal immunity played a role in his choice of where to live out the rest of his days.
Lena insists immunity played no role in Benedict's decision. If the former pope does travel to another country, Lena said, he will be afforded the same dignities and protections given to any former high-ranking official.
While the Vatican prepares the monastery for Benedict, he is staying in the town of Castel Gandolfo in the papal summer retreat which is technically part of the Holy See.
The Vatican also has legal treaties that govern relations with Italy and many other countries and could provide additional protection from any legal action.
Still, some attorneys who fear Benedict will be targeted say they worry about the broad powers European magistrates hold to take legal action on behalf of their own citizens.
Nicholas Cafardi, a canon lawyer and professor at Duquesne Law School in Pittsburgh, who has worked with American bishops on abuse prevention, noted that in Europe, magistrates can, among other actions, arrest and detain officials before any trial.
Next month, the Survivors Network of those Abused by Priests, which has been a leading critical voice against bishops in the United States, plans a conference in Dublin for victims of abuse worldwide.
"Americans don't appreciate the vast powers that investigating magistrates have in Europe," Cafardi said. "It only takes one who wants to make a name for him or herself to issue an arrest warrant for the former pope."