Advising a person to his face

What is the ruling on speaking directly to a person and telling him of his faults whilst he is listening? Is this permissible?

Praise be to Allaah. 

This is permissible if it is done in order to advice the person and rebuke him so that he will be deterred from committing sin. It should be done in a nice and polite manner so that the advice will be accepted. But if it is done in a mean-spirited way, intending to shame him, insult him and expose him to people, etc., then this is not permitted.