Since the history of mass tourism from UK to Europe afaik MM is the British 'disappeared' child. No one before, during or since.
Families regularly jet off to locations that present a far greater risk of child abduction than Portugal/PDL eg South America/Mexico and yet afaik there are no known cases of British children disappearing in these places?
I don't know of another case anywhere in the world where a child has 'disappeared' on a family holiday?
What features of this case make it unprecedented? Context is very important imo.
If MM disappeared at the hands of organised criminals why only her?
It wasn't only Madeleine perhaps suffering at the hands of organised crime.
Did you overlook the part in the link Misty provided
http://miscarriageofjustice.co/index.php?topic=7060.msg602811#msg602811 "The victims were, in the main, African migrants “among whom it was common to find minors ... "
Is it because the children are black their plight and the circumstances which enabled their transportation hasn't registered with you?