>According to your legal theory, if you now here say "no", you also committed also a crime since you admitted to helping me gain unauthorized access to a computer system.

Do you mean "no" as in "I won't try to crack it", or "no" as in "I tried to crack it and failed"? In the first case, I'm not helping you at all and there's no analogy with the Assange case. In the second case, it depends on the details of the law. I don't know if unsuccessful attempts to gain unauthorised access to a computer system constitute a crime per se in the USA. (I wouldn't be surprised if they do, given that e.g. attempted burglary is typically a crime.) In any case, if I tried and failed to crack the password as part of a broader effort to help with your (successful) efforts to break into a computer system, then I'd pretty clearly be an accessory to that crime. Intent is really, really important.

Ineptness is not usually an excuse. If I do a poor job of hiding the murder weapon for you, I'm still an accessory. If I stall the getaway car, I'm still going to jail along with all the guys who robbed the bank.

Note that in the Assange case, I don't think anything much hinges on the password hash. He's primarily accused of helping Manning to cover her tracks, independently of the failed attempt to crack the password.

The first amendment cannot be used as an excuse for aiding criminals hacking into computer systems. There is zero historical precedent for this, and it makes zero legal sense.

You are thinking of reporter's privilege, but massively overextending its scope (https://www.mtsu.edu/first-amendment/article/1146/reporter-s...).

Jorunalists are entitled to "protect" their sources in the extremely limited sense that they cannot, necessarily, be compelled to reveal information about them. They're not in any way entitled to shield their sources from law enforcement.