"The use of the internet to groom children, and the ability of young people to expose themselves to those risks is central to Jack's case," it said. "The lack of control over social media sites, and of apparent means to... prevent use by paedophiles for grooming children, are significant."
Concerns about Jack's internet use first arose after he told friends he was gay at the age of 13. He turned to online chat rooms where he arranged to meet older men.
The teenager from Bradford would even be picked up at school during lunch, taken away for sex and returned in time for afternoon lessons. On other occasions he travelled across the country.
He was referred to police by Childline in 2010, however the report said officers failed to investigate properly and the chance to "prevent harm was missed".
By early 2011 several agencies were involved. His mother found his plan to meet a 23-year-old man in Portsmouth to whom he had sent explicit images. Police seized his laptop and phone but did not start a criminal investigation.
Jack was also referred to social services by his GP and the NSPCC. However, social workers failed to follow child protection procedures, no single agency took responsibility and "Jack was not protected", the report said.
The teenager's "high-risk behaviour" and the offending against him was at its peak for the next two years. Throughout this time a trainee detective was in charge, with little supervision. "Opportunities to arrest and convict offenders were missed," the report said.
An investigation was only launched when his parents - both professionals with an older child at university - had a meeting with the Chief Constable of West Yorkshire Police.
Detectives eventually identified 36 adult male suspects - 20 were convicted for offences against Jack, including grooming and rape.
"The police seized Jack's devices, his parents restricted access," the report said. "At no point did this prevent Jack contacting men over the internet and social media."
The boy would borrow friends' phones or use public wifi. Facebook was one method abusers used to communicate with him.
Mr Ashley also discovered that "police were potentially powerless to monitor Jack's use of the internet because of current law".
The boy's father said the family's lives had "changed beyond recognition".
"It's hard to be with friends, we're too sad," he said.
"We cannot bear to think of what was done to his young and immature mind and equally to his young and immature body."
An inquiry was launched in August 2013 after a member of the Police and Crime Commissioner's staff heard about the case. A formal complaint against police was later made by Jack's parents.
The Independent Police Complaints Commission concluded nine police officers should face disciplinary charges, but four had retired by then. Two were given "advice", cases against two others were not proved and a constable was given a written warning.
In his report, Mr Ashley concluded that professionals "showed a lack of understanding", and "agencies failed to step up their commitment and involvement".
Yesterday in the UK Chief Superintendent Scott Bisset of West Yorkshire Police apologised.
He said better working practices were now used.
Susan Hinchcliffe, leader of Bradford Council, said she was "truly sorry" about Jack's suffering. She added: "Our procedures are far more robust now."
