Now I will agree that if someone has stripped your book and put it on all their friends kindles, ipads etc then yes that is unfair use.Robert Stanek said:Excellent points about your usage and number of devices. My thoughts really are specific to the scenarios I mentioned, and as an example: 10 devices, 10 users on 1 account all simultaneously having access to the same 1 purchase. To me, that is unfair use, if I have not expressly allowed it.
I will ask you one little question. Did you or did you not agree to Amazon's terms when you signed with them? If you agreed to their TOS then yes you have expressly allowed me to put your book on as many devices as allowed.