I once made a thread on this particular topic already and got a wealth of responses:
And as for a more direct example, my human warlock absolutely hates every race that are currently members of the Horde as he has a long history of being betrayed, attacked and invaded by them, leaving nothing else (quite literally as his entire household, everyone who was dear to him and the kingdom he hails from got wiped out in the many wars between the Horde and the Alliance) than his hatred and an investment in the Alliance military to constantly beat the Horde back and down until they cease for exist. He will freely smacktalk and use derogatory words (fitting the setting) when dealing with any Orc, Tauren, TRoll etc.
meanwhile I also have Horde characters who either despise the Alliance and/or humans on an equal level or ar indifferent. I am yet to get reported for my characters’ conduct though.