I think the problem is that the speed of the internet is causing most strategies to become obsolete at ever-increasing rates. Couple this with "observers" looking over your shoulder and pretty soon *those* strategies would no longer work to the same extent.
For IB, it might introduce more potential security issues to deal with. I'm sure the legal standpoint would have to be well-researched. A broker does not want to become an "accessory" to some potential problem.
For IB, it might introduce more potential security issues to deal with. I'm sure the legal standpoint would have to be well-researched. A broker does not want to become an "accessory" to some potential problem.