Also those which have been recycled, or which someone has locked out accidentally, or deliberately to scam someone ( https://news.ycombinator.com/item?id=7993435 ), etc. Used computers from companies often have BIOS passwords that no one bothered to clear before sending them off. Not every computer with a password its current owner doesn't know is a stolen one. That's why I think this is a good thing --- I believe in the fact that if you physically own something, regardless of how you came to own it, you should truly "own" it.