The brothers, now 11 and 12, were detained for a minimum of five years
Campaigners are calling for an increase in the term two brothers will have to serve for torturing two young boys in South Yorkshire.
The pair, who were aged 10 and 11 at the time of the attack last year, have been detained indefinitely with a minimum term of five years.
Pressure groups including Kidscape are appealing for the Attorney General to examine the case.
Police said a prosecution of the attackers' family was being considered.
Sheffield Crown Court was told how the brothers, who had been the products of a "toxic home life", lured their victims, aged nine and 11, to a secluded spot in Edlington, Doncaster, and subjected them to 90 minutes of violence and sexual humiliation.
They were strangled, hit with bricks, made to eat nettles, stripped and forced to sexually abuse each other.
Michelle Elliott, founder of charity Kidscape, said the attackers could pose a risk to society for many years.
She said: "I'm grateful for the indeterminate sentence but I would have urged a 10-year minimum sentence before they are assessed for release.
"I will be appealing to Baroness Scotland (the Attorney General). Several groups are doing that."
The psychiatrist added: "I think, for them and their families, victims need to have a clear 10 years."
Dr Elliott said the pair would be "better off" now they are in an environment away from the "feckless parents" who "dragged them up".
Michelle Elliott said the brothers could pose a risk for many years
A spokeswoman for the Phoenix Survivors, which campaigns for justice for victims of childhood sexual abuse, said it had already appealed over the minimum tariff "on the grounds that it is unduly lenient".
After the brothers, who admitted causing grievous bodily harm, were sentenced on Friday, South Yorkshire Police said it was reviewing the evidence heard in court.
When asked outside the court whether the brothers' parents should face a criminal investigation, temporary Supt Ian Bint said: "It's something we will be looking at with partners in the light of what has come out in court."
The court heard shocking details about the brothers' upbringing in a different part of Doncaster with their violent, alcoholic father, mother and five brothers.
Doncaster Council has apologised for the failures which allowed the brothers to carry out the attack.
A serious case review found the attack was "preventable".
The Audit Commission has now said it was considering whether to carry out an inspection into the running of the authority.