Published: May 17, 2011 3:42 AM EDT
Updated: May 17, 2011 3:42 AM EDT

SANIBEL, Fla. - Amazon's latest best-selling book is raising some eyebrows, both about its subject matter, and about digital piracy.

A New Hampshire dad wrote the children's-style book "Go the (bleep) to Sleep" for frustrated parents.  A digital copy of the book leaked several months before its publishing date, turning it into a viral hit. It's led to increased interest in pre-orders, and led the publisher to move up its release to June.

E-books are big business, with sales up 200 percent year-to-year according to the Association of American Publishers.

The rise in e-books have meant a change in business for brick-and-mortar bookstores.  Now online file sharing is increasing e-book piracy, putting both bookstores and authors on alert.

"I know a lot of my customers have it now, a lot of the younger ones," said Cassandra Early, whose Cypress Paperback Book Exchange Store has changed with the times in its 25 years in business; especially as some of her readers expand into digital technology.

Books still draw customers to Hollie Smith's Sanibel Island bookshop too, but not necessarily to buy.

"A lot of customers come in and want to get recommendations, but then they go home and put it on their iPad and Kindle," Smith said.

That evolution has led to a different way of doing business at the bookstore, including more gift and boutique items.

Best-selling author Randy Wayne White says he was originally nervous about the rise of e-books, but has found digital fans for his 'Doc Ford' book series.

The Sanibel author is also aware of the piracy problems that have previously plagued movies and music.

"I find it curious how people rationalize stealing someone else's work," White said.  "I find it curious and sad."

White says he isn't ready to panic about piracy in publishing, and even hopes there might be a silver lining.

"If someone pirates my books, they're thieves, they're breaking the law. But on the other hand, maybe they'll pirate one of my books, they'll like it, they'll buy the next one."

Digital publishers can put copy protection on e-books, but as with music and movies before them the system isn't fool-proof, and can be removed by hackers.