[BrentRitterbeck]

These high-frequency traders are not parasites. They are providing liquidity. Essentially, they are providing you a service. If your friend had not come along, perhaps you would have been holding onto your netbook for a lot longer, or it may not have sold at all.

If you want to see what happens when liquidity dries up, you only have to look to the Flash Crash. Yes, the whole thing started due to an erroneous trade, but the fall was greatly magnified when all of the computers were pulled from the market when they couldn't make sense of things. If this type of trading were to be banished tomorrow, the market would tank so quickly that people would be begging for the computers to be flipped back on. The genie is already out of the bottle, and it can't go back in without considerable pain to everyone around it.