Don’t waste time with anyone who will not share her or his first name.

This one may seem like an obvious red flag but you would be surprised at the number of people I’ve come across who have admitted to engaging in lengthy email correspondences with those who refuse to provide a real first name.  

While we must all be online-security conscious, we must also be online-security reasonable and it is unreasonable to expect anyone to take you seriously while you hide behind a wall of anonymity.

Mark