0xC4aE1e5 As mmmm has stated, legality doesn't do much and a child can still be targeted in ways both legally and illegally. This could be by any internet entity as well and for any purpose, from data collection by big companies to sexual exploitation by an individual.
Regardless, laws will not help anything, in our current state of society children are completely at the mercy of their parent and their parenting. Why I find it important for parents to understand potential dangers and how to minimize them in the most ethical way.
Why I find giving a child an unsupported device with no security updates, which they may use for any number of things, may not be a good idea. It could be a potential security and/or privacy risk that could be exploited by a number of people for any number of reasons.
Of course an attacker using a device exploit to collect information instead of using much easier methods is rare, and your child is more likely to be targeted in other ways online, but why keep the risk? Just my thoughts