Personal Intelligence
This is where you gather information on people without being too intrusive. The main principal is to follow their activites to see where they go and who they meet. The goal is to find out who is in their network and how they fit into their lives. You can go deeper into this and gather personal intelligence on the people they meet for a much more detailed over view.
This should be the basis of all long term information gathering. For once you have this information other actions can be taken to further the cause.
