I think what people also have to remember when dealing with these types of 'walls' is that it is very likely that more then one person made asks at $6.00. I assume you are using Clark Moody for your real-time data? Clark Moody combines bids of the same value so that they look like huge walls placed by one person while in reality it is simply a price point which people chose to sell their BTC at. Think about human psychology, we like nice round, even numbers because they are aesthetically/psychologically pleasing; which is also why when I make a bid or ask I use this fact to my advantage.

While fake walls can be a product of manipulation, I believe that in most instances it can be explained in other ways....anyways just my 2 cents.