R.I.P. Videotape
Ampex, from 1956 · generic in ordinary US use
The story
Ampex demonstrated the first practical videotape recorder, the VRX-1000, in 1956, and claimed 'Videotape' as its brand for the medium. It never had a chance: every broadcaster on earth used the word for the medium itself from the very first year, because there was nothing else to call it. No cancellation action, no famous judgment. The word was simply common speech before anyone got round to defending it.
The moral
Revolutionary tech needs TWO names: one for the brand, one for the thing.
One grave, one country. Genericide is decided jurisdiction by jurisdiction and class by class: the same word can be the generic name of a product in one country and a live registered mark for the same goods in another. What is described here is ordinary usage in the United States, not a decision of any court or office.