teachers and facebook
should teachers and their students be friends on facebook?
teachers knowing their students personal life out of school
That would just be plain weird. Your teacher you see everyday knowing what you say and do on Facebook. And the teachers could prenatally stalk your account and may say inappropriate comments.
They might treat and teach you differently in school.
If they see something you said on Facebook. They might judge you and that may affect your future if they grade your papers bad on purpose or they get you in trouble every chance they have. They might use it against you someday.
be careful of what you do
Don't friend your teachers or any person that your are begin taught by or teaching. Don't make the mistake.