In the article Outlawed by Amazon DRM, probably the worst of all cases of DRM is exposed. This is the sort of thing that gets your Open Source friends will use as a prime example of why DRM is bad, and quite frankly, they’re right.
The short version is a friend of the author had her Kindle wiped and her Amazon account closed with no explanation and no recourse. Talking to Amazon was like talking to a brick wall in terms of either a) getting it reversed or b) figuring out why.
Not cool Amazon, not cool at all.