if a teacher looks at your facebook profile and uses it against you in school...?

[Chazz]

Is it breaking the law? Because through that, she's invading your personal life, isn't she? I don't think teachers are allowed to do that.

I only ask, because my friend told me something funny about what happened to him when he had to explain the concept of a sick joke to a teacher with no sense of humour at all, and I said he should put it as his facebook status. But he said he wouldn't, because that specific teacher checks the students facebook profiles every now and then. To me, this seems illegal, and an invasion of your social life, because when we get out of school and actually USE facebook, it shouldn't be watched over by the teachers, should it?