Had it been my kid I would be out there every day asking around, putting up posters, making sure the cops were on their toes and garnering further support from the locals but...
John, everyone knows what they would do after an event don't they.
It's fine to say you would be out there every day asking around, asking where? who? Could they speak Portuguese? Kerry Needham tried knocking on doors, they shut their doors in her face, frightened no doubt by seeing a frantic woman gabbling in a language they couldn't understand.
It was the job of the police to ask around and do door to door.
As to posters, I seem to remember a photograph of the McCann's with a massive poster on the beach. There were posters in shop windows, everywhere you went according to Raymond Hewlett, who said that is how he knew Madeleine McCann.
As to keeping the police on their toes, how do you expect them to have done that? They had to write a letter asking for information, they didn't get a reply.