Teacher forcing me to delete social media?

[Talia Hemsworth]

A teacher at my school had obviously been searching up students names at the school, and has instructed me and my friends to delete our ask.fm accounts. My friends and I haven't been cyber bullied on it, nor do we ever have problems on it. I personally have no plans on deleting my account, but I just want to know if teachers actually have the right make us delete them? It's not like we have been using the site at school, so I don't understand what the problem is. Our school year is nearly over and a few day agos, this teacher threatened my friend by saying if we didn't delete it we would have detentions everyday next year. So, can teachers actually make us delete any social media sites? Thanks