I was thinking of that today as I had to download (for the 6th time since I started) a Kindle book I'm reading to my Android.
I'm another 1-2 downloads away from going on a torrent site and grabbing a DRM free copy that will actually stay on my local storage, be read on an app that does not take 30 seconds to boot, and not require large downloads with every open.
The natural evolution of that is to buy a copy on Amazon to support the author and industry, then download a free copy somewhere so you can actually read it in peace.