QUICK TIPS: BE FRIENDLY WITH THE FRIENDS OF YOUR ENEMY!
-- Be very general—don’t come across as having tunnel-vision about your enemy.
-- Pretend to be only semi-interested in what they have to say—they will share more information, if they don’t feel they are selling out their friend to a vulture!
-- Be very casual when asking questions—again, you don’t want to appear focused on your enemy.
-- Use your enemy’s buddies to feed strategic information to your enemy. (e.g., things you want them to know without telling them yourself).
There will be future posts on this topic in the near future.