Photos of an innocent boy have been posted online by people claiming he is one of the two 14-year-olds who murdered Ana Kriegel.
A judge has called those who share images of under 18s who end up in court "idiots", and is reminding them they can be fined and jailed.
Facebook and Twitter have been ordered to take down any material which could identify the boys found guilty of murdering the schoolgirl.
Lawyers for one of the boys told The Central Criminal Court that his family have had to go into hiding since pictures of him were posted online.
The family also said a tabloid newspaper reporter called to their home.
Legal teams for the other boy said photos of him wearing his school jumper were also being shared online.
A school told the court an innocent child has been wrongly identified as one of the boys in a Facebook post, which it has had trouble getting deleted.
The school also said other innocent children are being implicated, and a staff member is being wrongfully targeted online.
Because of their ages, the boys’ identities are protected by court order and by statute for the rest of their lives.
Mr. Justice Michael White described those who share images of under 18s who end up in court as "idiots".
Gardai have reminded anyone caught identifying a child who appears in court that they can be jailed for up to three years.
They can also be fined up to €10,000.
Facebook and Twitter have promised to continue deleting any posts that may identify either of the two boys.
The 14-year-olds are being held at a North Dublin detention centre until they are sentenced on July 15th.
As they are children, the judge will have some discretion in sentencing them.
A school report and a psychiatric report are among the factors he is likely to take into account.
