In order to control the distribution and use of their works, copyright owners are increasingly embedding access (keep you from accessing the work) and copy (control what you do with the work) protection schemes in their digital works. Under section 1201 of the Digital Millennium Copyright Act (DMCA), the circumvention of these access mechanisms is illegal, with only a few narrow statutory exemptions. The DMCA also prohibits the distribution of programs that can be used to circumvent both copy control and access control technologies.

The anti-circumvention provisions affect the way software engineers, computer scientists, and computer security specialists do their work. But the law also affects how librarians and educational institutions acquire new works, how Internet users can protect their privacy, and even how journalists can report on stories involving technical protection measures. By using a technical device to protect music, images or words the copyright holder can turn traditionally permissible access to or use of digital content into a civil violation. This new law has complex provisions and a few narrow exemptions, which are reviewed in greater detail in the DMCA anti-circumvention provisions FAQ, linked below.

Some activities affected by this law might include:

• manipulating the computer code of a digital toy to make it perform new functions;
  
• disabling an access control device on the storage media of an entertainment product;
  
• creating a patch for a software program or electronics product
  
• performing cryptanalysis on security systems that control access to digital data;

If you’ve received a letter accusing you of violating the DMCA, this section will help you understand the claims against you. If you are engaged in an activity which involves disabling an anti-copying measure, reverse engineering an encrypted computer system, conducting research on cryptography or security systems, or altering how a computer program or product works, this section is intended to provide you information about how the DMCA affects your activities. Distributing a program that performs these functions by selling, making available for download, or even linking to it, may also be a violation of the circumvention device provisions of the DMCA.