We are convinced that it is not slandering to say where one scholar has failed and is wrong and that it is our duty to warn the Muslims about it
for the safeguarding of our doctrin and our d�n.
Concerning this typical reaction Shaykh Gibril F Haddad wrote the following:
�There are notable exceptions in the Law to the prohibition of slander, i.e. of saying something unpleasant but true.
From the strictest viewpoint of the Law, the Prophet upon him blessings and peace, did mention someone's bad characteristics to warn others of the danger they represented. Another time he was reported to say: "Until when will you refrain from mentioning the wrongdoer [for the wrong they do]? Mention them so people can protect themselves from them!" or something to that effect.
So the prohibition of slander and backbiting excludes those that make no effort whatsoever to hide their transgressions nor are they repentent.
Furthermore, Allah Most High said:
{ Allah does not like the announcing of evil in public speech except by one who has been wronged; and Allah is Hearing, Knowing. } (4:148)
So the prohibition of slander and backbiting also excludes warning about a wrongdoer by someone that has been wronged.
Most relevantly here, such prohibition also excludes warning about innovators. As Imam Ahmad said, this is not backbiting nor slander but obligatory nasiha by and for those that truly fear Allah Most High, was-Salam.�
Hajj Gibril
* [The above text is an excerpt of Shaykh Gibril F Haddad's book:
"Albani and His Friends", which you can search and order on the web.]