Society has a duty to prevent child abuse. But in doing so, it must keep the broader interests of children – and everyone else – in mind. This second obligation seems to be in danger of getting lost.

Last week Britain began phasing in new rules requiring criminal background checks for every adult who works or volunteers in proximity to children. Many of the implications of this massive undertaking appear patently absurd. Children's authors who read their books in schools and volunteers who take minutes at meetings where no children are present will be required to undergo checks, to see if they have any criminal record.

The annual Scout Jamboree, in which 10,000 youth and 2,000 scout leaders from around the world trek to Britain, is also threatened. Organizers say it will be practically impossible to obtain police checks on all the adults from a wide range of different countries, before they arrive.

Canada has seen a similar, if less dramatic, escalation in the demand for volunteer scrutiny.

Police checks for coaches have become de rigueur for youth team sports, even in house leagues. Teachers and parent helpers are under strict rules to avoid any physical contact with their charges – including children who could clearly use a hug.

The underlying motivation for all these strictures is a genuine and understandable desire to protect children. The new British system was created in the aftermath of the horrific murders of two young girls by a caretaker at Soham Village College. In Canada, the former hockey coach and convicted sex abuser Graham James casts a long and dark shadow over the sport. The publication of Playing with Fire , the autobiography of Theoren Fleury, a former National Hockey League player, who played under Mr. James in the minor leagues, has renewed these painful memories.

But because of these rare but troubling events, every volunteer in the country now comes under suspicion, and organizations go to extreme lengths to insulate themselves from liability. The official erosion of trust has gone too far in Britain. Canada appears to be going down much the same path.

The entire social mechanism that creates and runs programs for children has become overly bureaucratic and, at times, even paranoid. Vigilance is one thing, a presumption of guilt is another. It discourages new volunteer efforts and unnecessarily complicates existing programs. In the name of protecting children, we may be leaving them worse off in the end. A better balance must be struck.

One place to start would be longer sentences for actual abusers. Cracking down on the real problem, instead of lowering a cloud of suspicion over all volunteers, seems like simple common sense. For all the pain he caused, Mr. James was sentenced to just 31/2 years; and he received day parole after half of that. Such lenient sentences surely do little to protect youths and children.