Ok so here is the deal you start a game and you are colonizing only to notice you have a buddy next to you. You scramble to get the best planets of course but as always the AI colonize anything not nailed down by your perverbial hammer. How do you fix this? Two ways
1: to qoute General Edmund Duke "well I Believe that qualifies as hostile"
or
2: You have lovely things that I like to call Faction Bases. Faction bases as you all know can increase your influence in a area that they are in. Influence can be a real problem if half your planets are in the hands of a potential enemy. The negative effect on your peoples contentment with your rule is the least of your worries as riots are a real possiblility for wayward colonies. Hence the Faction bases. Throw down a group of four around the system in question and watch in wonder as that system is now a island of your faction. Continue to upgrade the bases and before long those planets not under your sway will be feeling the hurt "spiritually" if not physically.
Hope this helps some new players