What is the digital millennium copyright act or DMCA?

The Digital Millennium Copyright Act or DMCA is a copyright law that makes it illegal to produce and distribute technology that helps decrypt copyright protected works. In addition to limiting the liability of online service providers for copyright infringement by their users, the DMCA also gives webmasters a legal course of action to request any internet service provider to disable access to a website where any of your copyrighted works are appearing without permission.

According to the Electronic Frontier Foundation the DMCA has not been used as congress envisioned. There have been some unintended consequences including.

• The DMCA Chills Free Expression and Scientific Research.
• The DMCA Jeopardizes Fair Use.
• The DMCA Impedes Competition and Innovation.
• The DMCA Interferes with Computer Intrusion Laws.

Here is a summary of the DMCA as provided by copyright.gov