Journalistic Integrity - Is this still a thing?

This line of thought was instigated by the watching of Kill The Messenger, the brief biopic of journalist Gary Webb starring Hawkeye a.k.a. Jeremy Renner. It followed the one man against the establishment, both government and mainstream news, trying to expose a government scandal about CIA and the cocaine epidemic. Emotionally twanging human story, but it got me thinking further about what this implied about journalism. 

Now, the only thing you can walk out of a biopic and know for sure is that the actual series of events was anything but this.
But, keeping that in mind, it still calls into question the entire construct of journalism. Is it anything beyond the spread of truth and the information of the populace? Is there anything that is too true to share ?   

I don't have the first shred of expertise to examine this from a general viewpoint, but I can look at in from the narrower sub-genre of science journalism.
What is it's purpose? To inform the general public about what science is, the work that scientists do, and why it matters. 

Is/Will there be anything in science that is too true to share?  It is definitely not beyond the realm of possibility. I can already think of things that may be societally unacceptable but necessary to the advacement of humanity, like human genetic manipulation, human testing, and other politically controversial matters like embryonic stem cell therapy. Science and maybe even the populace may be better having these things, but is there ever a case where any establishment is justified in its secrecy to withold information about it's use from the public?

Well, when you put it that way...Worth a ponder.