The online conversation may include readers whose presence the speakers never notice.

Most of an audience never speaks. A thread that looks like four people talking may be read by hundreds, among them someone the subject applies to directly, someone deciding whether this is a place they can be, and someone who will remember it for years. Speakers calibrate to the visible participants and forget the rest entirely. That is how a remark aimed at one person lands on people it was never about.

Before posting something sharp, picture one silent reader who is close to the subject. Write the version you would still be comfortable with if they said they had seen it.