Let's set aside whether or not the missionary is breaking the rules and focus on what was being blogged about. The only things he mentioned were their names and marital status. We don't know if the names were changed. We also don't know if he got their permission to blog about them. Is this really harmful? He didn't reveal any private things about their life. He only mentioned who he found. I have to assume that he will be respectful in future blogs and only mention general things about their lives (number of children, prior religion, how they were found, etc.) and won't divulge anything that shouldn't be divulged. Don't crucify him for something he has not done.