In Turn Coat, Harry is trying to get the lawyer to talk. When he finally gets her to start, she just physically cannot say anything, like she was being strangled.[/spoiler
Someone had bound up Ms. Derek's thoughts, alright, and woven those restraints together with her natural sexual desire, to give it permanence and strength.
They can dig into your head and implant things. Weave impulses with what's already there.
Imagine turning loved ones against one another. Two allies can become enemies, or at least not trust one another.
And the simple fact that people do
stupid things when they're angry. Anger and hate are blinders.