As you may recall, I've already stated my opinion that teachers should be wary about being facebook friends with students because it creates a disparity in the student/teacher power structure. This is more true with younger teachers who are having to deal with challenges to their role as an authority figure.
A new bill is being introduced into the Missouri congress that would ban teachers from being friends with students in these social networking sites. The bill's sponsor Rep. Jane Cunningham (R) says, "We're trying to make sure parents know that there is not private communication that is blocked from that student's parents or other school staff or administration." In short, it's for safety/PR/covering their ass reasons.
I'm personally against this type of bill. There are some teachers who use Facebook as a means of communication with students in responsible manners. They start groups for clubs and as a reminder for upcoming events. Facebook communication really isn't off limits to the courts and records of conversations between students and teachers could be subpoenaed and used. In short, a teacher would have to be pretty stupid to use Facebook inappropriately in that manner.
I suppose I should amend my previous position. Young teachers who have facebook profiles already shouldn't be facebook friends with students using that profile. If they want to set up an alternative profile just for school, then that might work out better. I personally don't want my student's writing on the same wall that my friends do.
I still don't plan on friending my students through either my actual profile or through a proxy profile any time soon. In the actual classroom, I'm more open to redefining the roles of student and teacher as I believe any good teacher is a learner and that any student has the potential to be a teacher in a self-directed classroom. However, in the social networking community, I rather leave those distinctions where they are. I'm willing to be a student's mentor or friend, so as long as the actions don't usurp my primary role as the teacher.
Edit: After thinking about it for a while on my drive to the Write to Learn conference today I decided that facebook friending students should only be done if there is some educational benefit from it. Otherwise, stay away.