Social networking site Tumblr said it was committed to continually improving its ability to act on self-harm content after a talented young teenager committed suicide.
Gifted young dancer Tallulah Wilson, 15, from West Hampstead, north west London, died after being hit by a train.
She became so obsessed by the internet that she created a fantasy cocaine-taking character to escape reality, St Pancras Coroner's Court was told.
The inquest jury found the teen took her own life on 14 October 2012, the Ham and High reported, and said in its narrative determination that six days before her death her Tumblr account was deleted at her mother Sarah's request.
"This contained inappropriate images containing self-harming behaviour," the jury said.
The mother's decision resulted in conflict with Tallulah.
"This site was very important to Tallulah, providing her with a medium to express herself over which she had total control," the jury said.
A spokeswoman for Tumblr said: "Tallulah Wilson and her family are in the thoughts of Tumblr and its employees.
"Issues of depression and self-harm are extremely challenging, particularly in online environments that encourage self-expression.
"Tumblr has policies to address the most harmful of this content, and we have systems in place to direct users to appropriate resources for getting whatever help they may need.
"We are committed to continually improving our ability to act on self-harm content, and also to keeping Tumblr a positive, supportive environment for those individuals dealing with issues of depression and self-harm."
Mrs Wilson said: "Our lives will never be the same without Tallulah. We have lost someone more precious than words could ever say - a beautiful, loving and talented shining star has been stolen from our skies."
She added: "Her sisters and I did everything we could to keep her safe, but she had fallen into a world of nightmares. She was in the clutches of a toxic digital world where in the final few weeks we could no longer reach her."
She was "shocked by the ease with which Tallulah and other children can access online self-harm and suicide blogs".
She added: "Tallulah entered a world where the lines between fantasy and reality became blurred. It is every parent's worst nightmare.
"I believe the likes of Tumblr should do more to protect other vulnerable young people from the insidious aspects of the internet; they need to take an active role in policing and swiftly removing unsuitable material as some sites already do.
"I appeal to big brands to withdraw their advertising from those sites who continue to host inappropriate self-harming and suicide-promoting blogs to stop this poison spreading.
"My family has suffered an irretrievable loss and would now appreciate some time to reflect and come to terms with a world eclipsed without Tallulah, but every parent needs to be aware of the dangers of the internet and what their children may be viewing online."
Coroner Ms Mary Hassell said she would make a prevention of further deaths report following the inquest.
During the hearing in the absence of the jury she said: "I think that I must pass on to the relevant organisation or organisations some of the learning that has clearly taken place as a direct result of Tallulah's death in terms of not simply the importance of the internet but the particular ways that it influences and the particular consequences that it has in 2014 rather than in 2013 or 2012 because it evolves so quickly."
The inquest heard that the teenager, once reportedly head-hunted by the Royal Ballet School, would go online and post pictures of herself with self-inflicted cuts.
A psychiatrist assessed her as being severely depressed in May 2012, but it had been hoped her mood was "lifting". She missed psychiatric appointments in the days before her death.
The jury said Tallulah experienced low self-esteem from an early age.
"Her mother is a normal caring parent, who had conflict with her daughter," they said.
She had difficulties with some girls at school and created an online persona.
"Her mother expressed her concerns and highlighted the dangers of this activity and the possible consequences," the jury said.
During this period Tallulah started to self-harm, which was noticed by the school nurse.
"It is clear she had a rich interior life which she guarded fiercely," the jury said.
On October 13 she met a friend she had met online. This meeting was uneventful, however it was without parental consent.
"When Tallulah's mother became aware of it, she challenged Tallulah, and this resulted in another argument."
On the day she died she was driven to dance class by her grandfather, but did not attend.
It is unclear whether she was depressed at the time that she took her own life, the jury said.
Rachel Kirby-Rider, executive director of fundraising and communications at Samaritans said: "Every suicide is a terrible tragedy and leaves devastated family members with many unanswered questions. The internet is playing an ever-increasing role in our lives and has become a place many vulnerable people turn to when experiencing suicidal thoughts and feelings.
"It is illegal to assist or encourage an individual to take their own life. A key challenge for supporting people who turn to the internet for information and support, is to deal with harmful content, while not limiting any positive support channels that are available to them.
"Current research on the effect that online interactions have on those at risk of suicide is inadequate, and Samaritans is looking in to new ways of reaching out to people. We would urge anyone struggling to cope to call us on 08457 90 90 90 or email firstname.lastname@example.org."