He sent an HTTP GET request, and the server responded. This isn't walking into an unlocked house. It's more like walking into an unlocked storefront during business hours, asking permission to view a certain item behind the counter, and being granted said permission by the clerk, who hands it to you.
> Just because he didn't use a crowbar doesn't make it any less intentionally criminal.
If those documents were not supposed to be viewable, the server should reject the request. Making a request is not a crime. You are literally asking, "Can I please see the document stored at $LOCATION?" If the answer is no, the server has a means to do that: send an HTTP 403 response.
The "unlocked house" analogy might hold if he tried to ssh into their server as the root user, but in this case, AT&T should have been held responsible for gross negligence for allowing people browsing[0] their open "storefront" (their website) access to personal customer information.
To use another analogy, if you submitted a FOIA request for classified documents, can the government satisfy your request (by sending you the documents) and then charge you with a felony for requesting those documents? I wager that most people would say that the fault lies with the government for failing to deny your request.
Publishing the documents later on is a separate matter, but the crux of weev's case focused on the fact that he obtained them, not the fact that he published them, which is maddening, because that logic would break the entire model of the web by breaking HTTP.
[0] Not to get too hung up on terminology, but notice that we use the term "browsing" the web to refer to HTTP requests, but we don't talk about "browsing" an ssh login.