Have the McCanns ever expressed anger against the person/people who took Madeleine?

I hear about the McCanns rage against the Portuguese police and against God, but I never hear them expressing anger against the person or people who took their daughter, if anything they seem to be addressing them in very humane terms. They say please just leave her somewhere safe and they indicate they are not interested in chasing them or bringing them to justice. I can't understand that, I would want to hang anyone who stole my child and probably abused her. It is clear they are able to express and feel these strong negative emotions, but why not against the person or people who actually caused this grief in the first place?