It is a not too infrequent part of the job of a PRO to encounter hostile contacts. To handle such, one has to be fast and effective at dead agenting. Every successful PRO knows how to dead agent and wins. Learn these techniques well. Never let entheta pass unhandled.
Prevention is better than cure.
Handle fast, handle with live communication, handle with documentation, use PR technology including tone scale evaluation. Notice that last line. Discredit the attacker. Now compare that with LarryBergen's accusations that all critical experts are liars and hateful bigots. By carefully watching press to see who is called upon by the press for counter-opinions, one can work one's way easily toward the centre of a hostile network.