The only other person in my house who plays Blockland is my 8 year old little sister.
We play in LAN once in a while, although I tend to use the banhammer to kick her alot, it is mostly just for fun. c;
Anyway, they probably have to, most who ban their relatives must have to un-ban because they suck up to their parents and you get this "let him back in or you are grounded" crap.