I saw The lives of others at the OU Film Society on Wednesday. Picking up on the role of information in the state and how information gives someone power over another, you couldn't ask for a better illustration. It is about the Stasi in East Germany (cf Sheds of Evidence), and their surveillance of a dramatist and his girlfriend. A trivial 'information' point, of course, is that if you were doing it today (as I'm sure some states are) the data would all be handled and stored digitally.
Perhaps more interesting, though, is to wonder to what extent we are willingly making information about ourselves available to the state or anyone else. Personally, I've stopped using my Tesco 'clubcard' for that reason, though I know it is a pretty poinless gesture while I'm still using credit and debit cards, posting on a blog and even putting stuff on Facebook.