Bounty has basically zero influence on who I decide to attack. While manipulating pirate attacks with it has use, the actual bounty itself is rarely worth the hassle. For one, the amount of bounty paid per ship killed appears to be an absolute sum rather than tied to any kind of proportionality, as I eliminated an AI player that had some 122K bounty placed on him, and yet did not receive all the bounty despite having annihilated him utterly! I've seen, at most, maybe $250 placed on a given ship, and honestly, to collect that money from an actual player would cost you more than you'd get back! Apparently, the bounty placed on a ship will not exceed the worth of the ship. If it did, I suspect the behavior of attacking a player for bounty would happen, but it would be utterly corrupted. In other games in the past, it *WAS* possible for a player's bounty to exceed his own worth, and when this occurred, the bountied player would actually willingly cooperate in the collection of his own bounty, since his profits from his own bounty could exceed his losses from being destroyed for it.
In addition, against human players, bounty is simply not a meaningful tool of diplomatic influence in ANY game: Your enemies are primarily dictated by factors of geography and history. In *ANY* game, you attack those who are typically your neighbors (otherwise it takes too long to get there and leaves your forces out of position), and of those, you attack those who you have fought in the past. In short, if you go after somebody for his $20K bounty, long after you have collected that bounty and any profit to be had is vanished, YOU WILL STILL BE AT WAR WITH THAT PLAYER. He is not going to suddenly forgive you when the attacks halt after the bounty exhausted. Humans are not inclined to forget such things casually: They will seek revenge. As most likely a committed war against a given player will cost you more than any bounty you can reasonably expect to collect, the cost of such a move will certainly exceed any short-term gain to be had.
On the other hand, a bounty COULD influence my choice of tactical shooting. If two enemies warp into my system with the intent of attacking me, both having equally threatening forces, I am going to choose to kill the one with the bounty first. Bounty, however, has no influence on my strategic decision of who to counter-attack. The strategic decision will be dictated entirely by geopolitics, and not by bounty. At the strategic level, bounty exists purely to buy pirates-for-hire. If a human player can afford to slap a million or more on a bounty for some other player, I would be more concerned about that player than the player he put a bounty on, unless for some reason the money involved somehow represents chump change, in which case, why am I risking my neck for chump change again?
Bottom line: Tactically, bounty can influence my targetting decisions, if it's sufficiently lucrative and relevant to my present situation. Strategically, it has no influence on who I will attack. If I attack somebody because he has a high bounty, it will be because I want to hit him while the pirates are hitting him, not because of his bounty, and I would do the same thing if another human player were hitting him even if he had no bounty.