Chontelle Sands is heading up the move, which was also prompted by arsonists and off-road trail bike riders.
She said rock throwers, who have provided nightly fodder for social media users for about a month, were the straw that broke the camel�s back.
�It seems like every night there is something online about it and this is really the thing that motivated me to get the group going again,� she said.
�What seems like harmless fun can obviously turn out to be something a lot worse. That�s why we as a community need to do something about it.�
Spearwood mum Andreia Volas said she was on a bus with her six-month-old son last Thursday afternoon when a rock was thrown at the windshield.
�I didn�t see how big the rock was but the noise was � wow,� she said.
�A normal car wouldn�t stand a chance.
�I don�t think I�ll be catching a bus for a while and I�ll drive around (the suburb) if I have to.�
Another on social media recalled how she was lucky a dent to her car was all she received during a recent incident.
�Twenty centimetres higher and instead of just denting my rear door it might have put my two-year-old in hospital,� she said.
A third person affected was a Yangebup local named Matt.
His parked car (pictured right) was dented when a rock was thrown at it around midnight two weeks ago.
�It really annoyed me having rocks thrown at my car for no particular reason,� he said.
�I don�t really understand how it�s still happening. I think more people should come forward and report it to police.�
Three people near the intersection of Osprey Drive and Tern Loop, a location reportedly notorious for the activity, said they had not seen anything themselves.
�I have heard it but I haven�t seen anything,� one person said.
�It�s mainly the hooning and the trail bikes (which are a problem).�
Ms Sands is organising a community meeting, planned for May 13 at the Yangebup Hall. Cockburn Deputy Mayor Carol Reeve-Fowkes said she would attend.