Last Thursday I wrote a piece about the case of Sullivan v. Ritz (and Faulk). I put the word armchair in the title because I'm not a lawyer and so my analysis was both simplistic and rather brief.
Today Mark Rasch released a much longer article on this same subject, "Mother, May I." As usual, Mark gives an excellent explanation of the underlying legal topics - the relation of physical world common law notions and rules concerning trespass. I highly recommend you read Mark's article if you're interested in the intersection of computer security and the law.
Mark also points to an excellent paper by Orin Kerr, - CYBERCRIME’S SCOPE: INTERPRETING "ACCESS” AND “AUTHORIZATION” IN COMPUTER MISUSE STATUTES. I read this paper some time ago and I've been searching for it ever since to no avail. If you're not a lawyer you usually don't have access to the right search engines/tools to find these sorts of things. Kerr's article is also an excellent read if you're not happy with the analysis the Mark gives of the current law, or you understand the analysis and don't like that words like "access" and "authorization" aren't well defined in the statutes.