The factor most dominant in PAS is the intent of the resident parent to cut off communications between the children and the non-resident parent (nrp).
In the past this has been fairly easy. Letters and gifts could be removed before the child sees them, and phone calls could be blocked or monitored. Schools and places where the children go could be informed to stop the absent parent visiting.
With the advances of technology these barriers can be bypassed to a large extent. A child with a mobile phone only needs to know the number of the absent parent to contact them directly without the knowledge of the nrp. Furthermore, many nrp’s will themselves have more than one phone number, a website, and various ways of being contacted indirectly through work, relatives, and friends who also have these facilities.
There have already been cases of children looking for their fathers via the Internet, and at least one child set up his own website specifically for this purpose. The non-resident parents who use these advances to keep lines of communications open have a considerable resource.