I actually met some of these kids when I was about 8. An old friend of my mom's she hadn't seen since high school got in touch and decided to come for a visit. She brought her two boys who were 7 and 9 I think. Most horribly behaved kids I'd ever seen. Hyperactive, rude, and had no desire to play or hang out. They just screamed and threw things around and trashed shit.
I later found out they were unschooled because the mom wanted them to grow up in an environment where they never heard "no" because that word would psychologically damage them or something. So instead of "NO!", she'd yell "TAH!" at them. Which had no effect. And she wouldn't make them be quiet, she'd just talk louder.
They did whatever they wanted, ate whatever, basically lived on cookies and candy and pop. Telling them no would have been abuse.
I remember they were pissed I didn't have Nintendo, and they made fun of me for reading and owning books, and threw my books all over. Also, the older one just walked over to my bed, puked all over it, then went right back to running around like nothing happened.
I only ever saw them that once, my mom decided her old friend was just too crazy. I'm almost curious to see if the boys grew up to be criminals or something.