Just thought this was interesting- http://www.goanwap.com/ebook-dix-list2-hbms.html
This site had a bunch of The Hardy Boys and Nancy Drew books online for download but has since been shut down by Simon & Schuster. There are also some other books on there, like Sherlock Holmes (which is legitimately in the public domain) and Enid Blyton books and The Three Investigators books (both of which I am pretty sure definitely are not.)
Why do they tease us so?? :(
Ugh! Found this site earlier today.