Hypothetical Question Would IB (or any broker) protect customers privacy the way Apple did during the recent FBI request to hack the terrorist's phone? Scenario Terrorists plan an "event" that would have a very negative affect on US markets. The terrorists accumulate lots of Put Options in the week leading up to the "event". The plan works and the terrorists cash in the puts. The FBI knows that there was unusual high put activity and has requested IB hand over it clients trading records. Would IB comply?
The FBI already has been given access to trading records in cases with accusations of insider trading. There is no privacy if you are suspected of committing a crime and a search warrant is issued.
Your broker will respond to any legal request from any regulator like the SEC, FINRA or NFA. I'm not sure about the FBI, but the request from the FBI might go through the regulator.
Maybe IB would secretly help the FBI through some secret "third party." That way, your trust is unshaken.