I just inherited my empire, and I am an outward catholic but secret Shia. I can see several of my vassals are also secret Shia. Is there any way I can use this information against them? Like, to arrest or revoke titles? If I send my chaplain to hunt apostates will he actually find them or just accuse random fools? If I refute shia and embrace catholicism, I assume the secret shia society will confiscate my copy of the secret membership roster and I won't know who they are anymore. Ideas?