Main Stream Media. Here at Websleuths, Terms of Service (TOS) specifies that anything presented as fact should essentially include a citation to main stream media or a law enforcement source -- usually a link. If a news outlet hasn't published information, it isn't information but rumor, insinuation, allegation, distraction.... IIRC, this protects Websleuths from legal action.
Posters local to a situation can become a Verified Insider by contacting the site owner &/or moderators.
Verified Insiders do not need citations or links.
"Insider" posts, often in long strings, are deleted without supporting links.