No, there is no DRM or anything like that on any Leanpub ebooks. Here's a little bit of information about Leanpub if you've just heard about us: http://help.leanpub.com/en/articles/110761-what-is-leanpub-i-m-asking-as-a-reader.
(If you're an author and you are concerned about privacy or curious about our DRM policy more generally, please check out this article: http://help.leanpub.com/en/articles/117407-should-i-worry-about-piracy-does-leanpub-do-anything-to-protect-me-from-piracy.)
Please note that just because we don't have DRM on our books, it does not mean it's ok for you to do anything you want with the file, like make copies and distribute them, either to other people or on a website, etc.
If you would like to purchase multiple copies so you can distribute a book to other people, here are the instructions: http://help.leanpub.com/en/articles/117458-how-do-i-buy-multiple-copies-of-a-book.