If you are using a microcomputer to dial-in to a York computer, transfer files to your personal computer to work on them locally, whenever this is feasible. Delete old files that you do not need. Label your backups. Licence infringement hurts everybody. Respect system security and integrity.
Security systems work best when all users respect their intent.
It is not York's policy to install elaborate security systems, because eventually this will deny all users reasonable access to computing facilities. Therefore, it is the responsibility of each user of a shared York computer to support security through personal computing practice, rather than depending exclusively on enforced means. Breaches of security are considered to be very serious offences. Obtain proper authorization for the introduction of any new external software.