To my knowledge, no one has ever been charged or sued for removing DRM from a book.
I don't expect anyone will be charged with that alone, because any perceived law against removing DRM for personal use is so likely to be knocked down in court. (the 5th circuit already says it wasn't the intent of the DCMA)
Amazon can see what's on your Kindle. Amazon is not the one who cares that you have DRM, though. Amazon says they are DRM-agnostic, and they have it disabled by default for those publishing through them.
Jeff Bezos says he does not think removing DRM hurts sales, and he says he expects publishers just need to get comfortable with the idea of doing without it. (videos and reports are googleable)
The only thing I would worry about is the possibility that a publisher could, on a wild-eyed DRM warpath, subpoena Amazon to give them the data they have on their titles that kindlers have de-DRMd. There does appear to be a "secured" flag on that tells whether DRM is still there or not, so...
But then we're back to whether or not a publisher even wants to push it. I don't think they want it in the courts, and I think Amazon would fight the subpoena, because they aren't as stupid as publishers are about PR.
But publishers could conceivably go crazy and decide to start sending out those strong-arming "give us $ or we'll sue you" letters like the music industry did.