Brenda - That is really bizarre, especially since Barnes and Noble developed the Nook! I've only had my Kobo for a week, but it's stood up to scrutiny and all that I've thrown at it so far.
Sam - I wonder if the confusion here is because we're a) stepping into a legal minefield, where there's a different between trademark, patents and trade names; and b) the source I'm referring to is talking about US law. Trademarks have infinite protection in the US, but that can be lost as soon as it becomes a verb.
In the US, you can happily call something an aspirin, even if it's not made by Bayer. But you couldn't call a computer an Apple, because they've retained the trademark protection there.
Basically we're talking about exclusivity. Think of the Duncan Yo-Yo trademark case in 1965. (See
http://en.wikipedia.org/wiki/Yo-yo#The_Duncan_era) Donald F. Duncan had stupidly released adverts with such slogans as, 'If it isn't a Duncan, it isn't a Yo-Yo'. That was used against the company in court.
Until then, you couldn't have said that your toy was a Yo-Yo, if you weren't part of the Duncan corporation. It would be like saying that my Kobo is a Kindle now. After that court-case, Yo-Yo became a legally generic world. Any company could use it. I could make one now and call it a Harrington Yo-Yo and Duncan couldn't touch me. They lost millions that way.
I've reworded it again for clarity.