But there's an obvious problem, from Twitter's point of view. If a term X is harmless in region A but problematic in B, then not only will right-thinking people in B be offended, but not-so-nice people in B may enthusiastically join in. Whether (and to what extent) Twitter ought to police such things is another question, of course.
He also quotes someone mentioning the 'k-word', which South Africans think of as we do the n-word. Now, this k-word is of Arabic derivation, and is also a translator's minefield. I remember back in Secondary School, I (not a Muslim) used the word "infidel" in jest to describe a (non-Muslim) friend, who didn't share my religion. I'd used it similarly to the dictionary definition, as in, someone who doesn't share my religion. Lord knows why. He said something like "Well, I'm not a Muslim, as well you know", though with more rage and schoolboy cuss-words. And, for the life of me, I've never heard 'infidel' used to describe a non-adherent of any religion other than Islam. It seems to have lost a big portion of its meaning, and become imbued with all kinds of ideas of how much Muslims hate us. Translating ‘كافر’/‘kafir’ into English is therefore tricky. Do we translate it into 'infidel', coloured with paranoid Western ideas about Islam, or do we lay our cards on the table and just say 'kafir', at least being a bit more open about the clash-of-civilisations shorthand we're using?