It's essentially like buying a real book and then giving it to your friends to read it, that you can easily copy an ebook so you can all read it at the same time is just semantics. Many times have I gone half and half on a book with a friend I would read it first because I am a speed reader then give it to him after. They could always delete their copies after, if they want to follow the letter of the law.
Don't get me started on school books, all of which I photocopied. No one said a word against it, not even the professor on the university who was the author of it.