Also it is almost impossible to give citations for leaked content. Credibility is a big deal for any journalist.
That's true. Although I guess things like screenshots, videos, etc might make up for that.
If I may interject here from a professional experience on the subject, I believe the problem is websites can actually be shut down for doing things like that.
allow me to explain. We, (the review site I work for) have to keep a good name in order to have the developers support us and allow us press passes and such. If we leak the info we can and will be reprimanded for it. Not only could we lose the support but they could actually sue us due to licensing and contracts. It is not worth the risk.
The risk of being sued/shut down is definitely there, but... quite a lot of journalists in other fields are willing to take that risk.
Need an example?
Private Eye (a satirical magazine) in the UK. Been sued hundreds of times. Lost a few of them. The editor is the most sued man in Britain. But they keep going regardless:
http://en.wikipedia.org/wiki/Private_Eye#Litigation
And the Guardian isn't exactly a minor newspaper. It still decided the risk of blowing the lid on PRISM and posting allegations brought by Edward Snowden was worth the risk:
http://en.wikipedia.org/wiki/The_Guardian#The_Edward_Snowden_leaks_and_intervention_by_the_UK_government
They also mentioned things like certain sites on Tor being shut down and criticise the US government and the NSA.
It's not just those either. A lot of UK newspapers seem pretty... well, determined I guess to do whatever they can to find news and sometimes stir up controversy, legality and big business/government be damned. They do go a bit too far (posting pictures of some enemy's tombstone and calling him evil or hacking people's phones for instance), but they at least seem to have some amount of guts.
Surely someone out there in the gaming press has some level of respect for themselves and their own values? No gaming journalists willing to do things even at the potential risk of their lives like those in other fields?