Perhaps if every member and poster on the group were in good faith, sources may be more openly discussed.
Unfortunately both media representatives looking for a story, pro life groups and individuals looking to shut down sources and distressed and grieving family and friends of those who have ctb wanting publicity to expose suppliers, all are well able to lie their way onto the Forum. Not to mention authorities who would also wish to close down sources and prosecute any of those involved. I'm not sure of the potential civil liability in various jurisdictions of the countries represented by members if an individual member was to be held legally responsible for directing a mentally disturbed person, or someone who turned out to be a juvenile, where to source SN.
It seems very obvious to me why there is reluctance to directly publish sources.