Many years ago I had someone on the net warn me:
in reply to On Online Communication
Not to attribute to malice that which can be explained by thoughtlessness
Actually, the original I heard had a diferent word in place of "thoughtlessness" but you get the idea.
It's worked pretty well for me, although it has left me with the impression that about half the net is... thoughtless.
It should probably also be modified to read "thoughtless, tired, irritable, not enough coffee, too much coffee, under pressure, or simply suffering a momentary loss of the sense of humour", but I feel that would take something away from the original quote.
I didn't believe in evil until I dated it.