In cases like this, a perfectly understandable emotional reaction is to wish for some level of retribution for this dreadful crime.
However, the state, and the law, do not act on emotional impulse, and have to consider all the facts, and the potential for future tragedy.
Reading the details of the ruling, it is clear that the judge is granting anonymity on the basis of the mental conditions suffered by the two girls in question, and serious concerns for their safety.
The law demands that suitable punishment is given to offenders, and yes again I understand that many people will feel that a custodial sentence with potential parole is not sufficient, but we have to abide by the laws as they stand.
What the law does not allow is for prisoners who have served their time to be released into potential situations where vigilante justice may be enacted, because that is not how the law allows society to operate.
Yes I understand the outrage and anger at the crime, and the perpetrators, but vigilantism is not the answer for crimes committed by people suffering from mental illness - that is not the approach of a civilised society.