Public profile: Facebook?

[Cassie]

Your current profile picture is always public, and so is your cover picture. You can't hide them completely, but you can hide the comments.

Click on your profile picture so it opens up, along with the comments. Then hover your mouse over the icon next to your name and date, and it turns into a button. You can change who sees the comments there. Set it to "Friends".

You may need to go through your old profile pictures too, depending on what setting they already have.

Read more in Facebook help center:
https://www.facebook.com/help/193629617349922

You can also read this article on Mashable about locking down your Facebook privacy. It takes you through everything step by step.
http://mashable.com/2013/07/09/facebook-privacy-how-to/