Corporate media
MSM is an abbreviation for "Main Stream Media", often considered to be the only credible (though still not necessarily reliable) sources for most of what we know and believe.
The MSM has often carried information tending to undermine "the official version" but does tend to shy away from anything that has possible intelligence implications, such as terrorism.
Some sources believe that the number of untouchable or "third-rail" stories is increasing rapidly with enhanced recognition and fear of terrorism in the general public.
In some cases, eg Andrew Gilligan claiming that the British dossier on Iraq had been "sexed-up", peoples employment has been summarily terminated even when there are no obvious secrecy implications to the information and only political embarrassment is involved.
WikiSpooks use of sources
WikiSpooks aims to use only credible sources but in many cases they will not be main-stream nor western. Unfortunately, they may not be subject to any "editorial process" as understood by western readers. However this is not a great problem when, for instance, they are reporting eye-witness testimony.