How Anonymous plans to use DNS as a weapon

Update 08-Mar-2012:
This is of course only a theoretical concept. A full scale DNS attack has not ever been conducted.

Update 29-Mar-2012:
Alright so Operation Global Blackout is fast approaching, i.e. 31-Mar-2012... That is the day Anonymous is supposedly going to take down the internet, using DDoS on DNS servers. Of course, there are varying theories around this threat, but all in all this still seems very unlikely to completely bring down the internet.

Update 01-Apr-2012:
The days comes and goes, and there is no evidence of even an attempt to attack the DNS servers.

Update: 26-May-2012:
So, anonymous fooled us (or joked or lied) about trying to bring down the internet. Of course, we all know a simple DDoS attack is not going to cripple the net. Here is an article that actually tells us how to kill the internet, and let me assure you, it ain't simple.