When you sell a Blu-Ray or a book to someone, they have the sole ability to enjoy it. But with computer files, there is no concept of ownership – you are simply given a license to use it – and courts haven’t gotten comfortable with confirming that a file is deleted on the first user’s computer. After all, files aren’t “exhaustible”; they can be copied an infinite amount of times. Or in crypto parlance, ‘double-spent.”
