In case you did not know: Packt is giving away free ebooks each day. The main downside is that you can not download them. You have to access them via their home page but on there, you can keep them forever access them on their page as long as it exist.
yeah, anything you can’t keep in your own physically owned medium is in the good graces of anyone who holds it for you. even if packt doesn’t revoke these books someday, they could still shut down or something.