Stronger: forbid all speculation online. Tamp it down. Take it offline, talk in private.
Investigate like a detective, with all your suspicions alert, following your intuition. But never speak publicly beyond the evidence. State only facts, never voice suspicions in public.
Speak like a prosecuting attorney, as aggressively as possible. But never speak beyond the evidence, nor prosecute beyond the evidence.
I am participating in a citizen detective-journalist action, trying to catch out domestic insurgents and nail them to the board. Disciplined thinking and speaking is critical to success.