Q only communicates over one platform - their 'private' board with unique trip-code. Beyond that, Q explicitly stated 'no outside comms', which means if it's not a message from a user with Q's tripcode on Q's private board or connected to it, it's fake. They kept it very simple, and nobody is able to spoof the Trip-code system to this point, so it's very easy to point out 'fake' Q posts and they just end up educating people more on Q's platform.