one must be very careful to avoid accidentally spreading dangerous information

The types of people who make attacks hadn't thought of it yet. The main obstacle to these attacks was psychological and intellectual, not physical, and once attackers realized these methods were effective the number of attacks of this sort began increasing

When you contain the source of a thought, that thought can change along with you as you acquire new knowledge and new skills.  When you contain the source of a thought, it becomes truly a part of you and grows along with you. Strive to make yourself the source of every thought worth thinking.  If the thought originally came from outside, make sure it comes from inside as well.  Continually ask yourself:  "How would I regenerate the thought if it were deleted?"