Facebook- a preventative measure?

Jean heard a speaker at ICE who told an unbelievable tale about students creating Facebook pages under some of the teachers' names. Their purpose? To damage the teachers' reputations.
anyhow, she strongly recommended that all teacher register a Facebook page in their own name, purely for the purpose of preventing others from being able to use it.So, I have a Facebook as well as a My Space page. I doubt I will EVER use them, but my children think i opened the account to spy on them. As if...!