Who was to say they couldn't be used to keep people out?
I used them to keep you out of my mind and will.
He used to keep about half of the pay back for himself.
These are data that will be used to keep people coming back.
The other hand may be used to keep the eye open.
I think she used to keep an eye on him.
Which is exactly why I used to keep it so short.
They have been used to keep them out of work and in labor.
But they used it to keep us in our places.
I've had the key all this time, ever since I used to keep you girls.