Quote from kjkent1:
This is probably an accurate analysis. However, I think it runs a serious risk of violating securities law, because IB knows or reasonably should know that no trading system can be successfully tested without actually trading the market.
There is no market without participation. Thus, if IB garners a large number of new accounts based on the contest, and traders who were successful in the contest and who are awarded prizes, then unsuccessfuly ply their winning systems under real market conditions, and are damaged as a result, then IB has mislead these people into losing money to IB's advantage and thereby violated Federal Securities law by inducing these people to trade using a false representation of a material fact, i.e., that a trading system can be successfully tested without actually placing trades.
Of course, unless one of the contestants is also a law student, this misrepresentation will probably not be recognized. However, the contest is a pretty risky proposition in general that could backfire against IB in a very expensive fashion.
All of this is only my opinion, of course.