I dont know about firms but I would think that certain individuals at those firms might piggyback a good trader if they had access to his trades.
Brokers, floor brokers and traders, and etc. asks programmers (system traders) to figure out how others trade. Happens... so what.... it doesn't affect how "I" trade. It might affect others...
I should mention that they're more after the institutions, they don't really mind about individual traders, unless they're very good. But they all try to hide the trades using multiple accounts and brokers. Floor brokers that is...
IB are interested in the option exchange power/politics they can have by threatening the exchanges with the SMART order routing code. What share of the options market do you think IB have?
I think the real threat is not someone laboriously reverse engineering your strategy or system but rather having a big position in a thin name. If I have the ability to know a hedge fund or hot money account has accumulated a big slug of some doggy stock, it is a simple matter to lean on it and try to run their stops.
A cousins brothers sisters friend said that if they have a profitable person they copy it mechanically to profit from it. That's not kewl, just a bunch of bad d00ds!
Let's say I'm a hotshot trader who everyone wants to be. (Hypothetical... I'm not OK... don't critisize me with the example) At one point, I give out my trading system to everyone out there. As a result, the market catches and my methodology doesn't work. By that time I'll have another strategy for the changed market condition. A trader needs to change or adjust based on the market condition. I think it's what a trader needs to survive in this business in the long run. I'm not saying I'm very good at it or can do it better than others. I always try to keep that in mind, trying to be changing at all times for the better. I've got a long ways to go though...
Most firms I talk with couldn't reverse engineer if they wanted too with the exception of extremely simple logic. If someone was that good at reverse engineering they would probably be on their own and no longer a broker or part of a firm which would put them on the same side of the fence as us traders.