You can’t control what you don’t have a stake in.

Likewise, you can’t be controlled if no one has a stake in you.

Jesus said the devil had nothing in him.  He didn’t say the devil had nothing on him, or no leverage over him.  Anyone can use information about you as dirt on you.  Anyone can use their perceived position, or your desires, to have something over you.  But the only real harm is when you let those things in you, let them claim a piece of you, let them have an equity share.

Let them do and say what they will.  Let them plot and scheme and attempt manipulation.  If you don’t need them, they have nothing in you.  If they have no hooks in you, you won’t turn when they pull their strings.