On the other hand, in one of the online lecture about Imam Bukhary rahimullah (sorry again, I don't remember which one), he told his companions that once he found the hadith about telling ghibah (backbiting), he promised that he would never backbite anyone.
This is interesting because in the science of hadith, credibilities of narrators are important. So what the muhaddithin did was if they found this or that person was not credible, they would write in their books that "This person did such and such (lying, etc)" or "That person did something that against the sunnah" etc. Therefore, people who read their accounts would ignore ahadith from those narrators that were deemed unworthy. But the way Imam Bukhary did was instead of telling everything that the person did, he would call them off by stating like, "We should leave this one out" or "There is something missing by this guy" or something similar.
As I see in this forum, people would say against others without having them to defend themselves and we should try our best to not to backbite against others that we never even meet. We are just known here as our screen names and I don't think that nobody knows what the person on the other side look like.