Secret ban
 

I know there was a hack for secretly banning a member where the member never knows they are banned, but they keep on posting as if they weren't.
Does anyone know where this hack is. I tried finding it but to know avail. Thanks in advance.

you mean that one?
https://vborg.vbsupport.ru/showthread.php?t=59718

There is also the stock Tachy Goes to Coventry which does what you are describing. Admin CP > vBulletin Options > User Banning Options > vBulletin Options > Tachy Goes to Coventry

No this isnt the one, even though its a cool one. I want one that bans a member and he/she doesn't know they've been ban. It will allow them to make posts and reply but know one will see it. LOl

Tachy Goes to Coventry does this.

Description:
This setting allows you to set certain users as being globally ignored. Their posts etc. are not seen by any users except themselves. This gives them the illusion that they are still functioning members of the forum when in reality nobody is seeing their posts. Enter a list of userids separated by spaces.

Doesn't that also hide all past posts as well?

All posts, yes

look for a post called "miserable user" don't ban them just let them die slowly he he it works i use it and they go away