“I AM a 19 year old girl and I am a victim of child sex abuse and child pornography. I am still discovering all the ways that the abuse and exploitation I suffer has hurt me . . . .” So began the victim impact statement of a young woman who was 8 when she was raped but whose abuse has never ended because the uncle who assaulted her took pictures that have been widely trafficked on the Internet. “It is hard to describe what it feels like to know that at any moment, anywhere, someone is looking at pictures of me as a little girl being abused by my uncle and is getting some kind of sick enjoyment from it,’’ she wrote.

The Supreme Court did not dispute her suffering nor her right to receive restitution from viewers who take pleasure in her abuse and create the sordid market demand for child pornography. But the court set aside the $3.4 million awarded her. Now Congress needs to fix the law.

The 5-to-4 ruling in Paroline v. United States is a double-edged sword for the advocates of child pornography victims. It upholds part of the Violence Against Women Act, which calls for restitution to victims such as “Amy Unknown,” as the woman is identified in court papers, but it limits the amount of damages proximate to the harm caused by a specific offender — a standard that puts the burden on the victim and makes it difficult to collect damages.

Doyle Randall Paroline, who pleaded guilty to possessing child pornography that included images of Amy, was ordered by an appeals court to pay all of the $3.4 million owed to Amy for the psychological damage and lost income she has suffered. The court’s majority, in an opinion written by Justice Anthony M. Kennedy, ruled that Mr. Paroline should be assessed an amount that is not trivial but comports with “the defendant’s relative role in the causal process that underlies the victim’s general losses.”

Justice Kennedy acknowledged that his approach “is not without difficulties.” How should a court calculate the harm caused by one person’s possession of an image seen by thousands? Mathematically dividing the total amount by the number of estimated views produces an amount so small as to be insulting rather than therapeutic. What, in short, is the right number between zero and $3.4 million?

The justices are right in thinking that Congress should revisit the issue. Legislation set to be introduced Wednesday by Sens. Charles E. Schumer (D-N.Y.) and Orrin G. Hatch (R-Utah) seems to be a step in the right direction, with its outline of options for full victim recovery when multiple individuals are involved and giving multiple defendants who have harmed the same victim the ability to sue each other to spread the cost of restitution. The court was clear in its opinion that “the victim should someday collect restitution for all her child pornography losses.” Congress needs to provide the tools to turn that someday into reality.