I'm not encouraging anyone to work on their own system. A shared network drive is just that.
Any user can, accidentally or otherwise, modify or delete any file.
Even if your network administrator makes back up of the system, it might not contain a particular file, or the most recent version. As the head of Sun recently remarked, privacy is something of an archaic concept. On many networks, users are set up with their first names as the network login and their last names as the password. It's very easy to change a password to something that only you know. When not in use, the disk would be stored in a secure, locked enclosure.