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Amazon is making it impossible to remove the DRM from Kindle Books
(goodereader.com)
This is a most excellent place for technology news and articles.
Back when Randall Munroe released his "What if" in eBook format, it essentially was only available with DRM.
When I emailed him about it, asking for a place to buy it without DRM, he responded with DRM unfortunately being mandated by his publisher, and finished his email with a link to this comic of his:
https://xkcd.com/488/