if data is stored via network instead of locally on the hard disk, then that particular data won't be stolen.
but i feel that since it's for public access (i mean the pc), i don't think there's much worry on security issues (i may be very wrong) as IT techs should have ensured that critical data or info isn't stored there. unless employees store file in there which may contain info or data which is sensitive to public.
kiya, u may have to ask the library techie about the security policy in that pc to know more. only he knows the actual setup, that is if he's the one who set up the pc.
hope that helps.