Source : Free On-Line Dictionary of Computing

padded cell
     
        Where you put {lusers} so they can't hurt anything.  A program
        that limits a luser to a carefully restricted subset of the
        capabilities of the host system (for example, the "{rsh}"
        utility on {USG Unix}).  Note that this is different from an
        {iron box} because it is overt and not aimed at enforcing
        security so much as protecting others (and the {luser}) from
        the consequences of the luser's boundless naivet'e (see
        {naive}).  Also "padded cell environment".
     
        [{Jargon File}]
     
        (1994-11-30)