A rude variation of the somewhat archaic (probably colloquial southern American) English phase "What you on about?" used when you have no idea what the other person is rambling on about and want them to explain what it's in reference to.
ted> OMG OMG OMG It's HUGE!!!
ted> Really, it's just so HUGE!! You wouldn'tbelieve how HUGE!!
fred> WTFYOA?!
So -- if you're thinking about using your starizon wireless cellular hotspot, just know that they wttfooy and you will have less than 1 meg upload speed.
This acronym means Wasn't Talking To You. It is to be used when people are in your business when they're not supposed to be or when people butt into your conversations uninvited. It can also be used to relieve confusion in a chat environment.