A questioned was posed to the Imaam Shaykh Muhammad Ibn Saalih al-Uthaymeen (may Allaah have mercy upon him):
Q."Has the Sunnah of Jarh (Disparaging/Criticizing) and T'adeel (Praising) died?"
A. "I fear that this is a statement of truth that falsehood is intended by. The science of Jarh wa T'adeel has not died, nor has it been buried and it has not become sick, and the praise is for Allaah. Rather it is standing. The science of Jarh wa T'adeel is used with witnesses in the presence of the judge. It is possible that a people criticize/disparage the disputant and the judge seeks from them the proof. Also the science is used in the matter of the narrations (of the people). We indeed heard the recitation of our Imaam (in salaah) the statement of Allaah:
"Oh you who believe, when a criminal comes to you with news, verify it"
(Soorah al-Hujuraat: 6)
Therefore the science of Jarh wa T'adeel remains (applicable) as long as mankind remains. So as long as mankind remains the science of Jarh wa T'adeel remains. However I fear that a person may say: This individual is disparaged and this one is not, taking from this fatwaa as a means to spead the faults of the people. Based upon this, if there is a fault within a person and the benefit, need or necessity requires that it be clarified then there's no harm in that. There's no harm in clarifying the matter. However it's better that a person says: Some of the people do such and such or some of the people say such and such. This is for two reasons:
1. The person frees (himself) from mentioning a specific name/person
2. This ruling will include the person (who is being spoken about) and others.
This is the case unless we see a specific person who the people have been put to trial by and he calls to an innovation or misguidance. In this case it's a must that the person be mentioned specifically in order that the people do not become deceived by him."
Taken from: http://maktabahuthaymeen.blogspot.com/2011/12/is-jarh-wa-t-dead-response-by-imaam-al.html