I never realized the dark theme on mtgoxlive looked so awesome
IMO large walls are largely irrelevant, they mainly serve as a showoff in the confidence game. The fact that they are moved so often lets me think that the Bids & Asks shouldn't be displayed in this fashion. Rather use some sort of decay parameter where orders become more relevant the longer they have been up.
Some of these walls move every minute or so and if we use this parameter they would show up as smooth curves instead of walls... So the 'manipulation' occurs when people attribute too much significance to them.
So my thesis is: If someone really wants to buy or sell at a price he'd make an order and leave it. Otherwise it shouldn't be considered important, at least only to the extent of time it has been up.
Of course in some cases were a large order has been up a long time and is suddenly hit the owner often pulls it which makes the whole thing more complicated.
This results to the conclusion that the order should be scaled by a binomial distribution curve of about a day. So one day old orders would be the most reliable ones and anything sooner or later than that takes less relevance