A digital rights management (DRM) licensing authority is strong-arming search firms, bloggers and open source advocates in a desperate attempt to stop the spread of a software key that disables copyright protection on Blu-ray and HD-DVD disks.

Copyright reform activist Cory Doctorow decided on Monday to remove the information from a group blog to which he contributes after receiving a cease-and-desist letter from the Advanced Access Content System Licensing Administrator (AACS-LA). 

The AACS-LA is backed by technology vendors including IBM, Intel, Microsoft, Sony and Walt Disney, and oversees the Advanced Access Content System (AACS) DRM technology used on high-definition DVDs.

The so-called processing keys published on the blog let users disable the DRM that prevents users from copying the disks or playing them on unlicensed equipment or software.

Doctorow is not the first blogger to receive a legal order from the AACS-LA. Several other blogs have been ordered to remove references to the key as well as links to a forum where it was first disclosed.

The AACS-LA has even issued legal threats against Google. 

The crack first surfaced in mid-February on a Doom 9 forum. In an act of defiance, numerous bloggers have posted the key on their websites or linked to the website detailing the original crack. 

They also submitted the web pages to social news services such as Digg in an effort to spread the information to a wider audience.

Ultimately the AACS-LA campaign has achieved the direct opposite of its intention. Instead of stopping the crack from spreading, the moves have notified more people of its whereabouts and how to exploit it.

A spokesperson for the AACS-LA did not immediately return a request for additional information.