What would happen if I set my Facebook profile pictures to 'only me'?

[Little Candy]

If I set my Facebook profile pictures to 'only me', when I return back to the option; 'friends' would any pictures get deleted, or would my friends' comments get deleted?

-Thanks in advance!
- @Annie J: Please read the whole details of the question

[Annie J.]

all that will happen is that you can only see your photos, veryone else sees the blue and white outline of a head

[Yousef]

Your profile picture will still be visible, not click-able.
No one will be able to click your " Profile picture " so you can change your profile pictures anytime you want without letting the people see what other profile pictures you have in that album.
Nothing will be deleted. everything will remain in it's place.

[shaquisha]

Only you would see your photo and nobody else. Nobody would be able to click into your profile pictures or your main photo for facebook. And no your photos or comments wouldn't be deleted.