Springy Answers

No! There are never any fines or fees associated with eBooks! 

When you borrow eBooks from the library, you're issued a time-limited "license" for that book. When the license expires, the book basically walks itself back to the library (if only ALL your overdue books would do that!).

Of course, it's not quite as simple as that. It may seem like you still have the book out, because the file will still be there on your computer or mobile device, but because the license is expired, you will get an error message if you try to open the book once the clock has run down. Think of it like a transfer slip that you'd get on a bus; you might still have the transfer in your pocket tomorrow, but it's not going to work, because the time code isn't valid anymore.