Comment by lusr

These people are using Facebook with the expectation it works like email. Why do you feel the two are so different? In my experience, the average computer user doesn't like fiddling with email addresses - Facebook is far more friendly (opportunity for a new email client?).

Email is not immune to these issues, either. This scenario is the equivalent to sending an email and having it end up in your friend's spam folder (although arguably Facebook should be more heavily invested in getting this right!)