While restricting viewer to members only, it wouldn't be that big of an issue for anyone wishing to read the posts to overcome. They could just apply for membership, even lie about who they are and why they're here, and then they have instant access.

The truth is, you shouldn't post anything online that you don't want known in the real world. I'm not perfect about this, but I'm more open about some things than others, even in the real world.