Shitballs is a word for an attention whoring idiot. It will constantly do its best to prove its gender on the internet, without actually providing proof. A shitballs is very likely to be found in chatrooms, linking her facebook pictures, and poorly attempting to troll users of actual worth.
"Shitballs laughed and posted her kawaii cat picture to the chatroom. Ah! My cleavage is showing! Don't hit on me, silly boys!"
"You want me to show you tits?! I can't do that, I must stay a perfectly pure virgin forever! ..... add my skype teehee!"
"Ugh, that bitch is totally shitballing. She should man up and post tits if that's the only use she has."