WTDTA can be used in any sentence were the phrase "where they do that at" may be used.
This meaning can be used anytime any thing unexpected, crazy, or weird happens. Also applies to situations where you are asked an absurd question, it can be used as an answer. Can sometimes be used to describe a good situation.
Just generally used to describe an exciting moment, whether good, bad, or funny.
#1 You see someone in a horrible outfit and say WTDTA
#2 You see someone doing something in public that they should not be doing and say WTDTA
#3 You just see something and think its funny and say WTDTA
#4 You get asked a crazy question and say WTDTA
#5 You see something you like and say WTDTA