The recent arrest of someone behind Silk Road is in the news today, he was arrested in a San Francisco public library. A couple of background articles here and here.

To what extent, if any, did staff and/or admins have in assisting law enforcement agencies in arresting this programmer? Did they voluntarily cooperate, or was it a legal requirement to cooperate under US law?

An answer from some authority saying Stack Exchange is not able to discuss the issue with users is also acceptable to me.