"Children exploit door locks to isolate themselves or others […] find innovative and potentially damaging applications for household objects […] knowingly and intentionally invite into the household guests that would not be welcomed by their parents […] escape the household and assist in the escape of both pets and of objects intended for indoor-only use […] perform surveillance operations which are invasive to the privacy of parents, siblings, or other members of the household," points out Schechter. "In short, children are both users of household technologies and adversaries against which these technologies must be protected.
In addition to being "insiders" - familiar with and trusted to use household systems - they are also natural hackers, as hacking the world is how they learn about it. But three things make them unique as adversaries: they cannot be banished ("laid off") from their home ("enterprise"), they are often a threat to themselves, and misbehaving is crucial for their growth.
"Designing security with children in mind requires a more nuanced approach than simply restricting access," says Schechter, and advises a number of approaches that should start you on the right path.