Here's an anecdote of my own past experience with Ameritrade many years ago (maybe 2004 or so):
I had a long stock position for some days or weeks. Suddenly the stock rose sharply because of a merger or something, and my position made a profit of about 16k. I haven't known that, I only saw that this had happened some days ago (then), and saw that the stock rebounced some points back (profit taking by the people).
I immediately closed and sacked in a profit of about 13k or so.
I got a phone call from Ameritrade who questioned me how I did that profit. He said that according to new laws (Patriot Act or such a thing) such a questionnaire were normal.
I really felt like in a Nazi police state...
I then switched to a different broker...