Mad circles (also known as interference or moire effect) seem to belong to the first wave of demos effects (even tho not as old as vectorballs or dots) as you can see some in the 1991 Ooh Crickey Wot a Scorcher demo by The Lost Boys. In my humble opinion this is more an effect to be seen as a transition between two screens or used as a demo filler. Yet if used with style and originality they can still be enjoyable to watch.
Mad circles can be described as two targets (from a darts game) moving around individually and crossing each other. Since they are made of a different color, each time they cross they create a sort of coloured interference (by the way that effect seem to be mostly known as interference by some people).
Sometimes the standard round shape can be replaced by a star or flowerlike pattern. As far as technique is concerned it makes no difference yet it ends up being way more interesting on a design point of view.
These mad circles look better than the usual effect maybe because of the slight distortion. Anyway it totally fits the perfection of the 2012 Muda demo by Live!. The show is fully enjoyable from start to end be it technically or in style !