This is obviously a situation where the community norms of MIT have collided painfully with the policies of its administration. Swartz thought the norms would be controlling; he miscalculated: it was the policies that mattered.
As far as I can tell it looks like "OMG! The attacker has changed his MAC address! We don't know how to stop him! He's stealing all the priceless research papers...call the DHS cyber-espionage defense unit for help! the packets are coming from INSIDE THE WIRING CLOSET!!"
MIT gives you wide power on the Internet. You aren't firewalled at all. I'm not even sure if they filter port 25.
But you also have the responsibility that comes with that power. The fact that they don't wrap you in bubble-wrap doesn't mean you can't hurt yourself or others.
So since Swartz was considered a guest on the MIT campus, he could hardly have been "breaking in" to this wide-open non-firewalled network.