The distress when a single child goes missing is enormous for the families involved. Surely no-one can fail to have been moved by the continued efforts of Kate and Gerry McCann to trace their daughter, Madeleine, after she disappeared while on a family holiday in Portugal in 2007.
Imagine the scale of upset, then, given the suggestion by one charity that more than 130,000 children go missing in the UK each year. The figures quoted by Parents and Abducted Children
Together (PACT) are staggering, beyond many people's comprehension.
Let me put it another way. According to the charity's founder and chief executive, Lady Catherine Meyer, a number of children equivalent to the entire populations of Preston or St Albans go missing every 12 months.
Lady Catherine's comments coincide with a point in the year on which focus on the topic is arguably at its greatest. May the 25th was originally designated Missing Children's Day in the United States in 1983 by the then President, Ronald Reagan. The date and the cause have since become fixtures on calendars around the world.
Last week, a specialist police child protection agency, the Child Exploitation and Online Protection centre (CEOP), relaunched a website (www.missingkids.co.uk) to circulate up-to-date photographs of and information about youngsters who have been missing for days, months or years.
The Home Secretary, Theresa May, also held a reception at Downing Street to draw attention and awareness to combined efforts to tackle the problem.
The statistics and the sadness which they cannot hope to convey in full seem bewildering. However, might they not represent one reason why measures might not be as effective as possible?
The reason is that no-one knows exactly how grave the problem really is. There is no central repository for data related to missing children. No-one can ascertain whether a child has run away from home or been abducted. If it is the latter, it's often difficult to establish whether that child has been taken by a parent or by a stranger.
Both, of course, are crimes but, say experts, different police forces categorise cases in different ways. Some do not apparently distinguish between abduction of a child or an adult.
When a child is abducted by a parent, the cases are not always immediately brought before the courts. Those parental cases which are recorded, though, make clear that the problem is significant.
Earlier this year, the British Foreign and Commonwealth Office (FCO) published figures on those children abducted and taken overseas by their parents.
It concluded that there had been a 10% rise year-on-year in incidents involving British children being taken by a parent to a country which has not signed the 1980 Hague Convention on international parental child abduction.
But ministers admitted that the actual incidence of the problem is likely to be far higher, as many such abductions never make it as far as the courts, politicians or law enforcement.
Trying to make progress in solving parental abductions is delicate enough without the lack of absolute clarity. The sort of parents whom I and my colleagues at Pannone have had to deal with over the years appreciate but generally discount the broader picture. Their principal concern is getting their own child back.
It is not, of course, a problem afflicting one family or one country. Whilst bodies like PACT, Reunite, the Ministry of Justice and the Interational Family Justice Office all do their bit to unpick difficulties involving British citizens, organisations such as the Hague Conference on Private International Law are at the forefront of wider efforts to create a simple framework for ensuring that the interests of the child are best provided for.
PACT is launching an appeal to find the money needed to pull together the various strands of information from the various interested agencies which could illustrate exactly how much and what type of difficulties exist. Such a step would provide a solid foundation from which to determine a coherent, concerted approach.
As a practitioner who has dealt with cases of parental abduction featuring almost every continent on the globe, any attempt to successfully tackle what the US Secretary of State, Hillary Clinton, described as a "painful scourge" has my endorsement.