Yelling fire in the theatre can actually kill someone. Slagging off someone on the internet won't exactly have the same effect.

Nor does exchanging the routine sorts of nasties with family, friends, neighbors, strangers, and work colleagues who don't fit the above categories.

Conflict is inevitable. Those who are in denial about that fact make life a living hell for the rest of us mere mortals.

I have never understood those who insist on imposing their "niceness" values on others, and demonizing everyone who doesn't share those values. Niceness is not a virtue worthy of sainthood, and it most certainly has an extemely negative dark side.