Is backbiting a dissolute person and a disbeliever permissible after their death, and does the absence of their inviolability mean that it is permissible to insult them and have ill thoughts about them?

It is permissible to insult a wicked Muslim and backbite about him if there is a prevailing legitimate religious benefit, such as someone who openly commits sins and whose influence remains after his death, in order that he not be emulated. Excluded from the prohibition of insulting the dead is anyone who was a hypocrite, a disbeliever, or openly displayed wickedness or innovation. This is restricted to what is legally permissible, and to the extent of the necessity without chatter or falsehood, and with a legitimate intention. As for the disbelieving ally (under a pact), it is not permissible to insult him or backbite about him except for a benefit; otherwise, it would be causing him harm. It is permissible to insult a belligerent disbeliever and backbite about him because he has no sanctity, whether alive or dead. However, this is restricted to the benefit and avoiding falsehood or exaggeration. Ill-thinking in the heart about a disbeliever is permissible.