The general tone of this thread seems to be that every parent in the world, if approached by the police, should happily agree to a DNA test on their child to prove the child is theirs and not Madeleine McCann.
I think the police would have to follow a process before they got to the stage of asking for tests.
1. They must have reasonable cause to think the child is Madeleine.
2. They must have a reason for rejecting any other proof offered.
If you broaden your horizon just a little you will realise there may be more children in the world who could be affected by separation from their nearest and dearest than Madeleine McCann.
One only has to look at the huge migrations occurring on our doorsteps where it is inevitable that children will become parted from their parents or their parents may die to see the inherent dangers children face.
I can foresee situations where DNA testing may reunite families.
I find this resistance of some to recognise the possibility that Madeleine could have been any one of a number of children sighted in the past extraordinary ... and I remain somewhat perplexed that you seem to think that DNA elimination tests should not be used to eliminate look-a-likes.
We are not talking thousands upon thousands of children being invasively tested here ... we are talking very few donating cells from a mouth swab ... and apart from the little girl dumped by the roadside in a suitcase ... none for a period of some years.
So is your objection uniquely applicable to Madeleine McCann ... or is it a generalisation applicable to all missing children?
Weird anyway that you envisage police conducting such tests without reasonable cause to do so.