347.Anas said, The Messenger of Allah (peace be upon him) said: "Help thy brother whether he is the doer of wrong or wrong is done to him." They (his companions) said, "O Messenger of Allah! We can help a man to whom wrong is done, but how could we help him when he is the doer of wrong?" He said: "Take hold of his hands from doing wrong."
(Bukhari).
Manual of Hadith by. Maulana Muhammad Ali).