The Digital Millennium Copyright Act of 1998 (DMCA)
WHAT IS THE DMCA?
As the internet took off, the internet tried to keep up. An important piece of internet content related information is called the Digital Millenium Copyright Act (or also known as the DMCA) which was passed in 1998. There are two most important parts of the DMCA when it comes to what happens when online. They both remain fairly controversial and remain controversial at this time (2008). The first one is the Anti-Circumvention Provisions.
If a copyright holder places some type of digital management software or hardware on a particular piece of content, it is now illegal for you to try to figure out how that works (reverse engineering), or defeat it. And it doesn't matter if you violate any of its copyrights in the process, just the attempt to circumvent the digital rights management approaches is itself illegal.
This provision allows for "Safe Harbor" for Internet Service Providers (ISP) and operators of various types of websites. This protects first and second party operators from third party attempts and successes in making changes or alterations, or copying and distributing in such a way in an otherwise manner that damages a third or fourth party.
More information online:
For more information in simple form, you can go to the following YouTube video provided by a second party which we found useful in this explaination.