[Jaded]

How you vote is a secret. How you are registered, and if you voted is public information.

So it's useless as the exit polling... for media results. I'd lie to their faces if they asked me.

[Fai Mao]

“So it’s useless as the exit polling.”

Actually, it is a very accurate predictor of the vote totals.
There are statistics on how many voters cross over to the other party. So it is very possible to predict what the total will be.