Do you think it should be illegal to look at the order book for a stock (public info), formulate a prediction, and trade on that prediction? Seems much differen

Do you think it should be illegal to look at the order book for a stock (public info), formulate a prediction, and trade on that prediction? Seems much different than a broker trading ahead of his client. Large informed traders and intermediaries like specialists/locals/market makers have been in a cat & mouse game since the dawn of time. Back in the day, big hedge funds would split their orders through multiple brokers or try to make their intentions. It's natural that one seeks to hide his intentions and buy/sell without moving the price the other wants to get the hell out of the way or trade with the big order. That's just competition.