They are scared that he will be "influenced" by other kids. Don't get me wrong, we all want to keep our older children and teens on a straight path and out of trouble, but most of us rely on the fact that we have brought our kids up to do the right thing and have to trust that they will. We also tend to be more in tune with their friends from a young age and know our communities (real life ones, not on-line ones). They don't spend enough time with their children, 1 on 1 as individuals to know them or what they might do in any given scenario.