I mean look at this guy.
I think he's saying "Oh boy, that's silly" and usually in a fairly innocent sort of way. But often times I see this thing in someone's post and think, "Wow, how smug!" It's something about his final expression I guess. Then there's this guy: 
I use him every now and then. Supposed to mean "neutral" or ambiguous but it almost looks a bit judgemental to me. Even worse: 
My last example, this guy is just sticking his tongue out and being cute, but I find it a bit impetuous. 
It's funny, I usually get more insulted (even knowing that no harm was intended) by those semi-neutral emoticons than I would if someone posted this:
"You're a big dummy!
"Just wondered if anyone else felt the same.
)