The historic sanctity of the seal of confession is being reconsidered by courts around the world—in England, Ireland, Australia, Louisiana, and in my own state of California, among others—specifically in regards to the crime of child sexual abuse. It begs the question why such a thing as the seal of confession even exists, and why Catholics would be willing to defend it if it means it might protect an abuser.

While it’s a big story right now, skepticism at the idea of the Catholic seal of confession is nothing new. See this English cartoon from 1865 that reflects the fear of a Catholic revival, and its mysterious confessiony ways. Laws protecting attorney-client, doctor-patient, and minister-penitent confidentiality vary from state to state and country to country, but Catholic Canon Law is very clear. A priest may NEVER reveal something told to him in confession, ever, for any reason.
Canon 983 says:
“The sacramental seal is inviolable; therefore, it is absolutely forbidden for a confessor to betray in any way a penitent in words or in any manner and for any reason.”
The punishment is excommunication for the priest. Canon 1388 states:
“A confessor who directly violates the sacramental seal incurs a latae sententiae excommunication reserved to the Apostolic See; one who does so only indirectly is to be punished according to the gravity of the delict.”
And not just the priest is prohibited from revealing the confession. Canon 983 continues:
“The interpreter, if there is one, and all others who in any way have knowledge of sins from confession are also obliged to observe secrecy.”
And in case you wanted to “but what if” it, Canon 984 says:
“A confessor is prohibited completely from using knowledge acquired from confession to the detriment of the penitent even when any danger of revelation is excluded.”
-1983 Code of Canon Law

A priest would be excommunicated for revealing information learned in a confession regardless of local law or the wishes of the penitent himself. As Fr. William Saunders explains, a priest must not discuss information from a confession after the fact with even the penitent himself.
For instance, especially with the advent of "face-to-face confession," I have had individuals come up to me and say, "Father, remember that problem I spoke to you about in confession?" I have to say, "Please refresh my memory" . . .
It’s easy to think, well that’s fine, but it doesn’t apply to EVERYTHING. We should be willing to make any sacrifice to protect children from abusers.
But let’s take a moment to think about what we’re giving up. Sacramental confession to priests has existed since . . . the evening of actual Easter Sunday.
Jesus said to them again, “Peace be with you. As the Father has sent me, so I send you.” And when he had said this, he breathed on them and said to them, “Receive the holy Spirit. Whose sins you forgive are forgiven them, and whose sins you retain are retained.”
-John 20:21-23 NABRE

Since the earliest written history of the Church, we find references to confession as private between priest and penitent. It’s true that through the middle ages penances were often public, but private confession was the norm. (See here for details.)
It’s not as if people’s sins have just recently become horrible/illegal/things we’d like to prevent. So we either believe in confession as a sacrament, as Jesus gave it to us, or we don’t.
The reason we are willing to accept the seal of confession even in the face of horrible crimes is because we believe that an even greater tragedy than a horrible crime, is a soul lost forever to hell. A confession with genuine contrition reconciles a person to God. I really think these laws are largely a veiled attack on religious freedom. But they’re also a not at all veiled vote for just damning abusers to hell for all eternity. And, as horrible as is their crime, we can’t want that. God wants their repentance and redemption. In charity, we have to want that too.
Now, one assumes that a person with genuine contrition would also want to try to make things right with the people he hurt, and even with society by turning himself in to the local authorities and taking his punishment. We hope that a good priest would give him that advice, and help him get the help he needs, or even make his absolution contingent on it. (Oops. Turns out that’s not possible, see the comments.) But the goal of sacramental confession is to reconcile the sinner to God.
We, as Catholics, must recognize the importance of defending the legal right of each and every person to seek reconciliation with God in a private sacramental confession. As reprehensible as are people who commit grievous sins that hurt other people, and I’m willing to go so far as to say that child sexual abusers are the worst of the worst, we can’t let our horror blind us to what’s really at stake here.

Yes, the Catholic Church failed again and again in her responsibility to protect her most vulnerable members from predators, and even more shamefully from the wolves among the shepherds themselves. We are suffering the repercussions of those shameful acts in our loss of credibility in public opinion.
But we cannot just accept that as a reason to sacrifice our hard earned religious freedoms.
It’s clear that good and faithful priests will not choose to incur excommunication by violating the seal of confession, therefore they could find themselves facing jail time. I don’t believe that the actual effect of these laws would be to protect children, nor do I think that’s the intent. I think the intent is to restrict religious freedom and to persecute good priests as a punishment for the failures of other members of the Catholic Church. As much as child sexual abuse feels like it’s worth sacrificing anything to prevent, these laws won’t actually prevent it, and will certainly result in further encroachment on the sacrament of confession in particular, and religious liberty in general.
It seems worth noting that the use of a confessional screen makes all of this rather a moot point for priests who might face imprisonment for refusing to violate the seal of confession. So I'm going to suggest we penitents go ahead and do that.
Further Reading . . .
This article is an interesting look at the legal side of the issue:
Louisiana May Jail A Catholic Priest For Refusing To Break The Seal Of Confession
And the (partial) resolution of that case:
Judge dismisses Baton Rouge Catholic Diocese, priest from lawsuit involving the confessional
Here’s an article that includes a look at a few of the particular cases around the world:
Laws Forcing a Breach in the Confessional Seal Are in No One’s Best Interest
A priest’s perspective on whether a priest can ever violate the seal of confession:
A very thorough look at the history of confession, particularly whether it has always been private between priest and penitent:
A history of the use of the sacrament of reconciliation in the early Church
And Watching . . .