I never have liked that phrase. It seems to me lately that I see it more and more. Unfortunately those people who seem to use it are on a self-destructive path. When they are cornered or confronted they lash out blast you with the “mindya”. As if that justifies their behavior. If you live a life that is glorifying to Christ and is respectable then you should not be scared of people knowing your secrets or offering their opinions or concerns.
Ultimately it is a lame defense and screams of a deeper problem.
passionburnswithin.com 
amen…but when that happens, do you “throw pearls before the swine” or wait till the devil lets them hit the dead end of that path or God breaks them and they come back to the church?
I think the answer depends on the situation. Not everyone responds the same way so use discernment. Tread lightly because the wrong move could drive them away for forever.