You have every reason to be afraid of dingoes, on Fraser (or anywhere - see later). There have been a number of attacks on Fraser, apart from the tragic death of the lad that Kev mentioned. The supposed 'pure-breds' on Fraser are a real threat in their interaction with people.
I know of three families that have been terrorised by them, similar to Kev's experience. So frightening were the incidents, that two of those families immediately cut short their dream holiday and left the island.
My partner and I have also been terrorised by them while camping (out of sea kayaks) between Sandy Cape and Moon Point (the inland side). We even had major troubles with them in areas where people generally don't go (4 WD's banned). They are dangerous dogs.
http://www.dailymail.co.uk/news/article ... beach.html
http://www.news.com.au/national-news/di ... 6437501031
Away from the island, who can forget Azaria Chamberlain's death, and the documented attacks on people at Uluru preceding that tragic event.
Completely wild dingoes are
usually cautious around people, but I wouldn't rely on that for my peace of mind ever, because they may not actually be pure dingoes. In my suburb Mitchelton in Brissie (9 km from the CBD), not long ago, near Lazybugger's residence, 'dingoes' were reported several times to authorities. Traps were set, and five very dingo looking animals were captured in traps, metres from residences. I personally saw one in the traps the authorities had set. It looked to me, as a lay person, very much like the Fraser Is dingoes which are supposed to be 'pure bred.'
But it wasn't. All five of those captured at the time were DNA tested and found to be cross-breeds with domestic dogs, and were then destroyed.
Herein lies one of the major problems. Cross-breeds can look very much like pure-bred dingoes, but may not be at all pure-breeds (as stated previously, even the Fraser pure-breeds are dangerous). How does this affect safety for people? The cross-breeding is most likely to introduce (to some degree or another) a reduction in caution of people, and so increase the risk of attack on people.