Someone buying a book without your knowledge could only be a problem if you don't have a computer or email account, since you are sent a message about purchases within minutes of purchase. Amazon will refund the price for several weeks after purchase and you can deregister the Kindle in minutes from a computer. I don't see this as a problem.
If you have any personal info on the Kindle, then that may be a concern, but no more so than carrying around a notebook with personal info in your pocket and losing it.
|