My original point is that Amazon has complete control over the Kindle you paid for. They can delete books as they wish and I would not be surprised if, upon proper court order, track your reading habits and/or your physical location.
Mine is that 99.999% of the time they won't.
Almost all limits on people's behaviour in society aren't around what they can or can't do, they're around what they will or won't do. If you annoy me I can stab you but I don't because society is structured such that it isn't in my interest to do so.
Behaviour isn't primarily only controlled by what's possible, it's controlled by what's rewarded and punished.
The same mechanism that prevents you from being a victim of random stabbing means that while in principal your eBooks are vulnerable, in practice they're safe.
Before I judge them on this I'm keen to hear their take on it. At the moment we have anecdotal evidence from someone who has an interest. If for instance Amazon had discovered the content violated certain laws that would be reasonable I'd suggest.
But you talk about it as if this is routine which is clearly a long way from the truth. I repeat, they're in the business of selling books. How many books will they sell if they keep deleting them?
Besides, if you're that bothered you can back up everything you own. If they delete the item then convert it to a different format and restore it. Yes it's work but so is Linux and you seem to think that's a reasonable effort to put into protecting yourself from this sort of thing.