Possible Changes

I'm seriously thinking about making my blog open only to those who I invite to read it. My mom saw a news report this morning about how people are taking pictures off blogs and exploiting people by editing the pictures with different bodies. I'm still experimenting with this because it appears that everyone has to have a google account to sign in to my blog this way, however on my permissions page it only asks for the email addresses of the "invitees". :) Any ideas on how I can make this easier are welcome, but my blog is already semi-private....except for the links on a few of my friends pages. I'm at a loss to know what else I can do to keep this from happening. I've been concerned about posting pictures of my children because of this very thing, and I'd never forgive myself if I just allowed it to happen without at least attempting to prevent it. I need feedback! :)