Shaykh Ahmed ibn ‘Umar Bazmool – may Allaah preserve him said – :
Those who are trustworthy and do not cheat; so they do not have secret gatherings, or hidden recordings, or secret slander, and their insides are the same as that which they display.
They do not say secretly that which opposes that which they say openly
They do not cheerfully great and welcome their Salafi brother that they are acquainted with in front of him, and then behind his back slander him and warn against him
From the lecture: The explanation of the narration of Ibn Mas’ood: How will you be when you are afflicted with Fitnah .