You know red, I believe that someone was deliberately pretending there were sightings to waste the Madeleine Fund money. Red Herrings to dry up the funds. To stop the searching, cos no money.
All had to be investigated
Quite, in addition to this (and this may sound harsh) - with the fund and the money sloshing around accounts - a cottage industry was born.
I recall very on, on the Mirror forum a poster calling themselves 'Steven' quite without shame asking around whether someone had a phone number for the McCanns so he could offer his printing services for leaflets and posters and suchlike.
Since then quite a few peeps have tried to get their slice of the action. That in a way was the monster the McCanns created - if I was, say a free lance journo or a criminal profiler trying to flog a booky - it would be very well in my interest to invent sightings - when reporting dries up re. the case.
It's parasitic behaviour - you feed on the host - but are very careful not to kill it.