I sent some privateers out to blockade, I heard money sounds and collected various little sums of money however I don't really get what's going on. How much area do they blockade? What effect does the blockade have on my enemy? Do they lose the money I am getting? Do they lose access to resources? What determines the amount of money I get? If I have a stack of 4-5 ships all blockading the same spot, do I get money for each or is this a waste of ships? What are some of the best way to use this?