I personally have never worried about it at any of them but that is just me.
That works right up to the point you have to explain to the Judge why it was you used your weapon when it was clearly posted. That sets you up nicely (never mind the criminal charge aspect) for an indefensible civil case from the BG's family (I know, it's insane, but highly probable).
I am curious without diluting the thread too much where do you draw the line? Other convenient stores that post no CCW? Schools? State and County offices?