User profile: give admin permission to hide/block each field complete

In user profile section optional entries several fields can be used by user. Some of the fields are from historical interest and not in real use in the moment. (ie. AIM, MSN, Yahoo!, ICQ).  Lots of school wish to hide this fields completly for students to avoid that they are filled with any data. Its possible for admins to hide the fields for other users but it should be possible to hide them for users generally.

It may be required to keep this fields for sites that use hem, so I suggest to give the admins the capability to define which of the fields can be filled by students and which are hidden for everyone. .