Laws of Rechilus / 7: 2 (101)

2. It is forbidden to speak rechilus even about an ignoramus, how much more so about a Torah scholar. This is so for numerous reasons: A. The ways of a Torah scholar are usually just, and therefore the rechilus spoken about him is probably false, which is a greater sin. B. By speaking rechilus about Torah scholars one causes people to distance themselves from them, which is against the Torah way. C. People are especially hurt when they hear that a someone of stature spoke badly of them, and this causes greater hatred.