Based on my experience, supplemented by careful and rigorous record-keeping, I have constructed an equation that describes the amount of emotional energy contained in various forms of impersonal nastiness:
In English: One nasty phone call is the equivalent of 50 nasty emails or 2,500 nasty tweets. Basically, a nasty tweet is all but meaningless. The bandwagon effect is so powerful on weak minds, and the effort required is so minuscule, that an outraged tweet is equivalent to only a tiny fraction of a nasty phone call. Nasty emails are somewhere in between. Keep this in mind if you ever get a barrage of nasty tweets.