Growing numbers of teenagers are being sexually assaulted or gang raped by other teens, a children's charity has warned.
Cari said it was alarmed by the dramatic rise in reports of attacks by multiple perpetrators in 2012, which doubled to 41.
Mary Flaherty, chief executive, said staff also recorded a 162% increase in rape and sexual assault allegations on under 18s, from 132 to 351.
She revealed teenagers told volunteers they often felt culpable in attacks, were witnessed or sometimes encouraged by others, and left traumatised by recordings which were viewed or discussed on social media sites.
"The sexualisation of children and young people and easy access to pornographic imagery plays a vital role in how young people perceive sex and sexuality," she said.
"The nature of our calls has changed so much in the past 20 years that this issue needs to be addressed.
"Social networking sites also need to play a role in child welfare and protection - which to date they have not done."
Ms Flaherty said a 13% cut in State funding last year impacted severely on services, leading to the closure of its service in Cork and all staff being laid off for a month.
Therapy hours had to be cut by 7% nationwide, from 2,650 hours in 2011 down to 2,474, leaving more than 50 children who were sexually abused on a waiting list for therapy by the end of the year.
Ms Flaherty said it was an appalling indictment on the nation that some of the 3,300 youngsters who report abuse to health chiefs each year are being let down.
"Children in Ireland continue to be sexually abused every day and we continue to fail them," she said.
"If you are an adult who has experienced abuse, either in the last 24 hours or as a child, you have access to counselling in every health board area. You also have rape crisis and domestic violence units nations.
"If you are under 18 you only have support two children's hospitals in Dublin and a service in Limerick which we run."
The helpline took 1,493 calls during the year, up 4%.
They included 1,182 where a child spoke about their ordeal, 208 silent calls which were seen as a victim's first step for help and 104 that went unanswered due to resources, a 30% drop on 2011.
The majority of allegations involved a family member and some parents raised concerns over the sexualised behaviour of their teenagers, although no abuse had taken place.
Cari, which also supported 64 children or family members through the criminal courts, also criticised the three to four year delays in cases which impact on a child's life and healing process.
Majella Ryan, acting national clinical director, said the long term effect of child sexual abuse on children when they do not receive the appropriate interventions is well documented.
"Children as young as eight years old present with thoughts of suicide, self-harm and mental health issues," she added.
"Many struggle at school as a result of their experiences.
"When left untreated, they can go on to develop problems with addiction, social skills and many other things that can make life difficult and unbearable.
"When these children are made safe and receive the right intervention, they can move on and the abusive experience does not have to define them."