The site has a main focus on BB. But not everyone joins to talk about BB.
I will say that personally(I think my opinion on this is pretty common knowledge

), I dont think there should be a filter. However, I can see why there is one.
Its all well and good saying parents should supervise their kids 24/7, but in reality, its not quite that easy is it :/
And I would be so pissed if I had kids who had joined a forum to talk about..say the x factor...and ended up learning words such as ****** from it.