Journalists have already testified in this case to the contrary of what you said. I.e. They do help sources stay undetected, providing advice and sometimes help where appropriate.
Similarly, military and political practice don't define what is and isn't illegal in connection to launching and justifying wars, frequently and repeatedly killing innocents and journalists, setting up a highly illegal system of secret sites and covert armies explicitly for the purpose of abducting people globally (including random innocent members of the general public) and torturing and killing them, conspiring to lie about it all to the general public, then phoning up your cronies and launching a transparent international extra-legal persecution of someone who has embarrassed you.
But it should. The law should follow morality, ethics, and common practice. If the US law is beyond that, then it is overreaching and tyrannical. But of course, especially with these leaks, we already knew that.
Morality and ethics are not universally shared among people within a country. Consider debates in the US about abortion, same sex marriage, imprisonment of illegal immigrants... The list could go on for a while.
> The law should follow morality, ethics, and common practice
Whose morality, ethics, and common practice? The fact that this leaked and almost nobody cares means that people have made a decision. They want the government to have wide latitude to protect them from terrorism, and they care more about that than prosecuting this purported wrongdoing.
>The fact that this leaked and almost nobody cares means that people have made a decision.
Most people have made the decision that the government is corrupt, Assange is an asshole, and there's nothing they can do about any of it because their elected officials are also corrupt.
That is hardly an endorsement of all the horrible things that the US government has been secretly doing in their name.
Yes, two things can be true at the same time: The US does some bad things, and Assange was trying to break a supposed hash to help Chelsea Manning steal more stuff.
That may not be the case when the first amendment is applied. Consider Heller vs DC, in which the Supreme Court ruled that firearms in common use for lawful purposes couldn't be banned under the second amendment. Standard practice can be a factor when constitutional protections are at issue.
