The biggest problem that I have is ascertaining the intent of a poster, sometimes. Depending on how it reads, a post could be from someone attempting humour or a humourous discourse, being blunt, acerbic, waspish, or really trying to establish themselves as a total arsehole.
If someone takes that post the wrong way, the original poster may then find themselves feeling obliged to defend a position that s/he doesn't fully support.
Been there, done that, both sides. Nowadays I try to imagine being face-to-face with the poster, and respond as I would in that case.



Doesn't always work, though.