Australian police are joining the Five Eyes allies to demand big tech companies help fight a disturbing increase in crime, including young men using online networks to encourage sadism and self-harm by their targets, primarily young women.

AFP commissioner Krissy Barrett spoke of the "worrying" new trend as she prepares to meet with global law enforcement agencies.

Australian police are joining the Five Eyes allies to demand big tech companies help fight a disturbing increase in crime, including young men using online networks to encourage…