Calls for young people to "cut themselves" in protest against Justin Bieber's burgeoning interest in cannabis have prompted outrage.
Young Minds, a children's mental health charity, hit out against the "irresponsible, reprehensible and extremely dangerous" behaviour of what it branded 'Twitter trolls'.
Pictures of the pop phenomenon Bieber apparently smoking a joint had triggered a mock campaign from users of the social media website 4chan.
Some of the images posted appeared to be using vast amounts of tomato ketchup in the name of satire, but other pictures looked gruesomely realistic.
Fears that some of the pictures, encouraged by Twitter's #cutforbieber hashtag dominating the microblogging states in the US, could be genuine prompted starlets like Miley Cyrus to endorse criticisms of the meme.
Lucie Russell of Young Minds said self-harming should not be dismissed as a "fashion, fad or statement".
"It's a signal that young people are experiencing extreme distress and need help," she said.
"Cutting is a self destructive act that is a way of coping with overwhelming emotions.
"To suggest young people cut themselves as some kind of protest is a very perverted and dangerous idea, and these people need to take responsibility and stop this activity immediately."
Each year 25,000 children and young people are admitted to hospital because of the severity of injuries caused by self-harm, the charity claims.