A couple of days a go, my friend Linn sent me an e-mail, being very frustrated: Amazon just closed her account and wiped her Kindle. Without notice. Without explanation. This is DRM at [its] worst.
See also this post in the Kindle Help Forum.
Update (2012-10-22): Jonathan Rentzsch:
Fortunately Apple’s iTMS DRM dog never barked. But after today’s Amazon Ebook controversy I decided it’s time to share my similar Amazon Ebook Insurance Policy[…]
But on Monday night, after a number of websites had written about the case, the account was restored and the 30-40 books that Nygaard was available again. […] IT consultant has not yet received any explanation or apology from the company. She believes the massive attention to the Amazon has helped to get the matter resolved.