Why are some ebooks readily available as PDF?
<p>There are some ebooks that are readily available as PDF, and can be downloaded from multiple sources. For example, "Effective Java" by Joshua Bloch can be found easily on the web. There are even repositories on Github containing multiple ebooks on programming.</p>

<p>In "Effective Java" the following paragraph can be found:</p>

<blockquote>
  <p>All rights reserved. Printed in the United States of America. This
  publication is protected by copyright, and permission must be obtained
  from the publisher prior to any prohibited reproduction, storage in a
  retrieval system, or transmission in any form or by any means,
  electronic, mechanical, photocopying, recording, or likewise. For
  information regarding permissions, write to: (...)</p>
</blockquote>

<p>Why is it so easy to find these PDF versions, and why is no action being taken here?</p>

<p>There are any number of reasons, but they'll probably fall into one of the following.</p>

<h3>Permission was given</h3>

<p>The site hosting the file has been given permission by the Copyright Holder. <strong>Permission</strong> is a defense to copyright infringement.</p>

<h3>The Copyright Holder is unaware</h3>

<p>The Copyright Holder is unaware that their Work is being infringed. Third parties have no general obligation to make the Copyright Holder aware of infringements, except where required by law.</p>

<h3>The Copyright Holder has decided not to pursue action</h3>

<p>The Copyright Holder has made the decision not to pursue legal action for any number of reasons, for example reputational damage or the costs of proceedings.</p>

copyright internet