This is a great question, and one I'm sure we all grapple with.
I realize the question is specifically addressed to the Orthodox brothers, so while I am not qualified to answer from that perspective, I can offer my own thoughts on the matter.
"Love the sinner, hate the sin" is the oft-quoted Catholic answer.
But beyond that, beyond praying for those troubled souls, what else do we do? There is a sort of grey area here.
There seems to be a conflict between action and reflection. Between righteous indignation and quiet prayer. Between good works and good words. Doing good is not simply being nice and harmless constantly, but often involves great difficulty and careful assessments of another's character, ability or motivations.
It seems if we follow things far enough to their literal conclusions, all our actions are impotent to some extent, and all our judgements or remedies ultimately futile (because this is up to God).
I think this is an area of confusion. Many people think Christians are just a bunch of passive pushovers, because we aren't supposed to fight back. But my understanding of "turn the other cheek" is giving someone the benefit of the doubt, and leading with good faith. Once that trust has been broken or abused, however, you don't continue turning your cheek indefinitely.
If this isn't understood or expressed correctly it can lead to a vicious loop of anger --> guilt --> repression, etc.
