Journalists seem to talk about "X, the service formerly known as Twitter" or similar - I guess they have to call the company by its official name but also want people to know what they're talking about
Shouldn't that be pronounced Kitter or Chitter?
The only official pronunciation of X in English is "ks", and there are many languages that use X for many different sounds. Shitter is appropriate, I think some Spanish dialects might read it that way.
Also in English x is pronounced as z at the beginning of some Greek-derived words like Xerox and xylophone.