People will trash their brother behind their back. They seem to justify their unloving speech because it is not a lie. "Its okay I'm only spreading the truth." When people do this they are not walking in love. There is no good will towards their brother. There is no desire to help turn a brother away from ways that are hurting him and restoring him to God's ways which are good for him.
When a person walks in love they want to restore a brother not trash him publicly. There goal is to restore their walk with God not to disgrace them in the community. Notice in the passage below that every effort is made to first privately speak to the brother with the attitude of restoration. Then if that doesn't work then its okay to slightly enlarge the private conversation by adding another one or two in the hope of restoration his walk. Then only if the all else fails then it is to be told to the church. But even in telling it to the church the goal is to have a community motivator, although unpleasant, drive the person back into right relationship with God. Loves goal is to restore and not to speak evil of others. What if God aired all our dirty laundry from our lifetime just because it was true. Thankfully God is willing to cover our sins and doesn't maliciously spread our moral failings.
Matthew 18:15-18
15 “If your brother sins, go and show him his fault in private; if he listens to you, you have won your brother. 16 But if he does not listen to you, take one or two more with you, so that by the mouth of two or three witnesses every fact may be confirmed. 17 If he refuses to listen to them, tell it to the church; and if he refuses to listen even to the church, let him be to you as a Gentile and a tax collector. 18 Truly I say to you, whatever you bind on earth shall have been bound in heaven; and whatever you loose on earth shall have been loosed in heaven.
( please note there are exception is the Bible where it was in the best interest of the church to handle a situation immediately and publicly)
Scripture quotations taken from the "NASB" (www.lockman.org)