Child killer Mary Bell, who was convicted of murdering two young boys when she was 11, has been granted lifelong anonymity.
Mary Bell was a child herself when she killed two young boys
A High Court judge decided on Wednesday that the identities of Bell and her daughter should be kept secret to protect them from vigilantes.
Bell has been given several assumed names since her release from prison in 1980.
Her current identity and whereabouts cannot be disclosed under the terms of a temporary court order, which also covers her teenage daughter.
BBC correspondent Andy Tighe said the judge, Dame Elizabeth Butler-Sloss, stressed the case was "exceptional" and it did not mean that a blanket of anonymity would be granted in all cases of this kind.
Bell, now 46, was convicted of the manslaughter of four-year-old Martin Brown and three-year-old Brian Howe, in Newcastle in December 1968.
The judge heard that disclosure of 46-year-old Bell's current identity and whereabouts would lead to harassment.
But outside the court Martin Brown's sister Sharon said the decision was "a mockery".
"The victims are not the heart of the subject - no one was interested in our family," she said.
She said the family had hoped the government would have set guidelines preventing Mary Bell from profiting from any books or films associated with the case.
Newspapers had already withdrawn their opposition to the case and the attorney general, representing the public interest, effectively supported it.
The key issue before the court was whether Bell's right to privacy and family life outweighed the competing claims of open justice and press freedom.
The judge said the granting of the injunctions was for reasons that were different from those behind her similar decision in the case of Robert Thompson and Jon
Venables, the killers of James Bulger.
Martin Brown was four when he was killed
Dame Elizabeth's ruling two years ago which granted lifelong anonymity to the schoolboy killers - on the grounds that their lives were in serious danger - had been the only precedent to Wednesday's case.
She said : "The granting of the relief sought by the claimants in this case is not ... a broadening of the principles of the law of confidence nor an increase in the pool of those who might in the future be granted protection against potential breaches of confidence."
BBC home affairs correspondent Danny Shaw said that if the High Court had decided not to grant Bell anonymity, it would be "one of the legal shocks of the year".
Speaking to the BBC in April, Martin Brown's mother June Richardson said: "The best that could happen would be for her to remain anonymous and just vanish and we can get on with our lives."
Her daughter Sharon said the family bore no malice towards Mary Bell's daughter, but had "no feelings" for the convicted killer.
This is such an exceptional case ... Mary Bell today is not the person she was when she was 11
Gitta Sereny, author of book on the killings
In April 1998, reporters lay siege to Bell's home after it emerged she was paid for helping author Gitta Sereny write about the crimes.
Ms Sereny said on Wednesday that she understood the anger of the victims' families, but called the decision "justified".
"This is such an exceptional case, but I think any child who is in this situation as an adult or child needs this protection.
"Mary Bell today is not the person she was when she was 11."
She said the killer had not asked for payment for her contribution to the book.
"She would have talked to me without money," said Ms Sereny.
Dame Elizabeth's ruling on Thompson and Venables had led to accusations that the courts were protecting criminals.
Bell was given a new name and had her identity protected by the Home Office when she had a daughter.
That protection would ordinarily have ended last May when Bell's daughter turned 18, but a temporary injunction was granted pending the outcome of the legal proceedings.