About four months ago the Advanced Access Content System (AACS) encryption used for HD DVD and Blueray disks was cracked, sort of. What happened was that the encryption key was discovered and with the key the content can be accessed, which of course also means that it can be copied if someone wanted to do that.
The group that handles AACS has recently been sending out "take down" orders to Google and various other content providers to remove sites that publish the now widely-known key.
Digg.com users recently revolted when Digg began removing posts that linked to the key. Eventually Digg gave in to its users saying that it will no longer remove such posts, and that the company will take whatever legal heat that brings.
Given the fact there are funny pictures of hamsters disclosing the key, t-shirts with the key on it, and even a guy who got the key tattooed on his chest, it doesn't seem like Digg stands much a chance of getting sued over what is now public knowledge.
Besides, new HD DVD and Blueray disks will use a different key, so any cracking tools won't work against those.