I’ve read the full text of the letter (as posted by the Wall Street Journal) and let me say that it is much, much odder than a mix tape.
Reportedly your government employs extensive security, protection and intelligence systems—and even hunts its opponents abroad. September eleven was not a simple operation. Could it be planned and executed without coordination with intelligence and security services—or their extensive infiltration? Of course this is just an educated guess. Why have the various aspects of the attacks been kept secret? Why are we not told who botched their responsibilities? And, why aren’t those responsible and the guilty parties identified and put on trial?
Stone crazy.