I had a chance today to look at the last Torah lesson Rav Nahman of Breslov said in his lifetime the Le.M. vol. II, chapter 8, and I thought to bring here a few of the ideas he mentions there. 

One idea he says is not to give rebuke because unless one has great merit, because he can make things worse by giving rebuke in the wrong kind of way.\אף על פי שתוכחה היא דבר גדול ומוטל על כל אחד להוכיח את חברו כשרואה בו דבר שאינו הגון אף על פי כן לאו כל אחד ראוי להוכיח כמו שאמר ר. עקיבא תמה אני אם יש בדור הזה מי שראוי להוכיח כי כשהמוכיח אינו ראוי הוא יכול להביש את השומעים את תוכחתו  ["Even though rebuke is a great thing and it is incumbant on every person to rebuke his friend when he sees in him something not proper ,still not everyone is fit to rebuke as R. Akiva said, 'I would be surprized if there was anyone in this generation that is fit to give rebuke,' because when the one who gives rebuke is not fit, he can cause damage and make ugly the souls of those who hear his rebuke."