"Someone wrote something on my Facebook page and I don't know if I should delete it or not. Could you take a look?" This is not the type of phone call you want to receive as you're trying to shut it down at the end of the day.
I don't think these comments are offensive but it does rise a lot of questions/thoughts about how Twitter is used as a collaborative exercise. Can someting be done in a similar way in education and if so does it need monitoring/censoring???