The top answer to this question is appalling, and utterly wrong.
,Does not matter whether you monetize the copy or not.
,Does not matter whether you credit the author or not.
,Making a derivative work (that is the legal term) of a copyrighted book, without permission, is illegal the moment you do it.
Put it in public, and the statutory damages in a settlement could ruin your life.
Get off this site and talk to a copyright attorney.
Itu2019s pretty hard to avoid copyrighting it, under present law, since itu2019s automatically copyright the minute you set it down in final form.
,If you mean why should you register your copyright, I donu2019t know u2014 why? What work are you talking about u2014 a photograph? A novel? A treatise on how sunburn damages the mesodermic layer?,Generally, unless you have a realistic expectation that someone else might try to exploit your work without your permission, registering it probably isnu2019t worth the trouble.
,If youu2019ve written a novel, and youu2019re trying to sell it to a traditional publisher, registering the copyright is a mistake.
It marks you as an amateur.
Ordinarily the publisher takes care of the paperwork of registering the copyright in the authoru2019s name, the author isnu2019t expected to do it.
Whatu2019s more, nobody wants to steal unpublished novels by unknowns; thereu2019s no money in it.
,If youu2019ve written that treatise on sunburn, whatu2019s the point of registering it? Whou2019s going to want to steal it? (I donu2019t know, maybe thereu2019s a hot market somewhere for plagiarized articles on dermatology, but I never heard of it.
),On the other hand, if youu2019re a news photographer and you got an amazing shot of some major event, you might want to register it, because people do swipe nifty photos.
When this was passed in 1998, it was completely impossible for sites that allow user uploaded content to look at all of that content and know it if was violating copyright law or not.
Yet at the time you could sue YouTube because someone uploaded a movie clip or used music in their video without permission.
,What the DMCA does is create a new system.
In order to sue a website like YouTube, they have to fail at following the steps that must follow after the content owner informs them that they have illegal content on their website.
The steps are (summarizing):,Tell the website that they have a post that uses your content.
,They remove the content and allow the uploader to appeal the DMCA takedown.
,The content owner answers the appeal or relents.
Depending on this, the website may restore the content (they donu2019t have to).
,The content owner may, regardless of the outcome, start a lawsuit against the uploader, suing them for damages.
The website has to give them what information they have so the content owner can properly name that violator in the lawsuit.
,The most common criticism is that people can falsely claim they own the copyright on the original content in order to troll the uploader.
This is illegal under the DMCA.
But the problem is that enforcement is done by the uploader suing the false claimant in court.
This is expensive and a huge burden on small content creators, so most donu2019t do it and trolls are emboldened by the lack of consequences.