Surprisingly Promiscuous Sharing Behavior of Facebook Photo Tagging, Wellesley, MA
Even Mark Zuckerberg’s sister Randi was surprised by the promiscuous sharing behavior of photo tagging.
The setting that controls whether your photo appears in a tagged friend’s feed for his friends to see is in his settings, not yours. Your best defenses are:
don’t tag friends in your photos and posts, and
turn on tagging moderation so that you can review tags that others add to your posts.
Any time someone is tagged, his privacy settings control whether his friends can see the post, regardless of who originally created the post and regardless of the privacy settings the creator originally chose for the post.