You have a blog which isn't connected to your real name in any way.
You write about something totally cute that your child did on your blog.
You're laughing about the same cute thing your child did with a co-worker who is a friend.
Another co-worker walks into the breakroom and overhears the story and laughs saying she'd read the same thing on one of her favorite blogs earlier that week.
You don't write about work at all on your blog.
You don't blog while you're at work.
Do you fess up that you're the owner of that blog or do you keep it moving?