It was MIT's network, not a government network. The network was not "secure," campus guests can use it though leaving a computer connected 24/7 in a wiring closet (that could have been locked but wasn't) clearly exceeds the campus policy. The JSTOR link makes it pretty clear that his activity, including that which involved using the hidden computer, came before federal involvement. Given the language of the Computer Fraud and Abuse Act, I think the outcome could have been the same for an MIT student or faculty member, it would've mattered to the federal attorney. JSTOR's and MIT's hands were tied in the sense that they were not party to the aggressive prosecution of Swartz, the federal attorney had a lot of discretion as to how to handle the case and chose to be very aggressive.