John Frame, The Doctrine of the Christian Life (Phillipsburg, NJ: P&R, 2008), 843:
Many theological controversialists today set themselves up as Internet gurus, declaring brothers and sisters to be excommunicate on their say-so alone, showing contempt for the authority of the church, which alone has been authorized by God to make such judgments, and violating God’s standards requiring protection of the accused. Many of these have no scruples about spreading lies to anybody who will listen. It never occurs to them that they have a responsibility to protect the reputations of fellow Christians, even those with whom they disagree.