A portmanteau of 'OS' ('Operating System') and 'hostility'. I would suggest this word to describe:

OStility is at present restricted almost exclusively to computer-related media. Judging by the strength of feeling involved however, perhaps it’s only a matter of time before people take it onto the street.

I initially considered the existing English word 'ostracism' as a good candidate for this definition, particulary since it neatly contains both 'OS' and 'racism', and was therefore fairly evocative of the meaning. I settled on OStility because it is a new and distinct word. Why invent a word at all? Because this phenomenon clearly exists, and as yet has no specific single word to describe it since (at the time of writing) it is a relatively new and specialized concept. Recognizing trends and concepts and finding new ways to deliniate and vocalize them is one of the many ways in which language evolves. And evolution is good.