If you are using a microsoft program as you network gate, in theory,
anyone has full access to your hard drives and all non-removable media
storage- ie anything that is online. There ae selections you can make to
change the defaults involved & limit accessablity. Remember if a hacker can
access your drives, they can download anything they want, as well as sending
you viruses, or even reformatting. This is not meant as fear-mongering or
perpetuating a hacker scare mythos, merely pointing out worst case scenario.
Being a consultant on such matter, I am continually amazed at how few lines
of code are required to destroy any entire system.
    Another point to keep in mind is that viruses are so difficult to prevent
with certainty, that anti viral software relies on huge databases, constantly
updated, to keep track of all presently known ones.
   The other side of the coin is that hackers have an unwritten ethos, and
cultural institutions such as museums are generally not targeted for
destructive activities -though occasionally they will send you a message
letting you know they are there.
   You should probably have a risk analysis done by a qualified systems
security expert who can them make the necessary recommendations.
    If you are serious about your inolvment in computers, information
technology and virtual media, then you should give serious thought to hiring
by contract a departmental director. In todays world it is not just the
hacker threat that is the danger, but the risk of being left behind.

If I can be of any additional help, contact as above.

             Dion