How could anyone steal a harddrive from a library? Amazing.
IMO thieves wouldn't get any possibility to steal your passwords or data, if it's stored on your server, but they'll learn about your IP addresses and open ports, so they could perform a DoS (Denial-of-Service) attack.

And if you gaze for long into an abyss, the abyss gazes also into you. -Friedrich Nietzsche-