Shared systems are also more vulnerable to mischief and accident, and their hard disks tend to become littered with files of unknown origin. For these reasons, some lab managers and system administrators install software that inhibits changes to system files and restricts what can be placed on the hard disk and where it can be located. FoolProof software published by SmartStuff Development can help prevent alterations to system files and other hard disk changes on a shared Macintosh, although it can probably be subverted by anyone who is determined to do so. Quantity discounts and educational discounts are available.
Shared systems are also more vulnerable to viruses.
More information on virus protection and eradication is online. Software on shared systems also needs to be monitored to make sure that licensing restrictions are observed. Licenses granted with an educational discount may be strictly limited to instructional or research use. This can be very convenient, but it can also be more risky than you might think. When a Macintosh with file sharing enabled is added to the campus Ethernet, its disk can potentially be accessed by all other Macintosh users on the campus Ethernet, not just those on the same LocalTalk network.