A judge has issued a stern warning about vigilante activity following the circulation of "Wanted Dead or Alive" notices in Castlebar, Co Mayo.
The threatening literature has been dropped through the letterboxes of nine families.
The circulars were brought to the attention of a District Court judge, who said she was "outraged" by the development.
At a court case in Castlebar, where a number of young people appeared relating to criminal incidents, Judge Mary Devins warned that any suggestion of vigilante activities would be treated most seriously.
The circular, she was told, was delivered by post and identified nine families. It stated: "Wanted Dead or Alive for anti-social behaviour". It suggested that a reward was being offered in connection with named families "and also girlfiends" (sic).
Mr Aiden Crowley, solicitor for five youths who face 77 charges, said the circular was a very dangerous development. The gardai, he said, were charged with investigating crime and did a good job, and the courts were charged with determining innocence or guilt. "It is not for any private person to take the law into their own hands", he said.
Judge Devins said there was only one law in the State, and that was enforced by the gardai and the courts. "It is too easy for people to get excited, for tempers to flare and blood to boil."
Insp Jerry Henry, prosecuting, said the mother of one of the accused contacted him in relation to the circular and said it was causing her great distress. Gardai, he said, took a serious view of it. They were satisfied they had the resources, knowledge and ability to cope with the crime wave.
An investigation had commenced, and gardai intended to pursue it vigorously and to find those who had produced the posters, Insp Henry said.