I am pretty sure it isn't the first person, but the last person with bounty. If all the bounty is gone, they continue to go for the same mark over and over. I have had pirates attack the AI non stop for the game because no one was doing bounty. I may be wrong though (I dont think I am).

Admittedly the pirate behavior is regarded as a problem.  There's a reason why everyone plays with pirates off in multiplayer.

Forgive me if I seem like I'm complaining allegiance, I don't mean for it to come out that way.  I'm just new and trying to discover and understand the game.  I actually love the game if I didn't like it I wouldn't waste my time figuring it out.  I'll try to sound less "negative" from now on.

i think the defualt targets are random but it will always start with the first player in list. pirates once attacked me twice with no bounty.

I'm not saying that the pirates are impossible to handle, only that there's really no benefit to being attacked by them, other than possibly having a capital ship in the area that could get a level or two from it.  I usually always have my forces on the frontline though, and I don't have the time or resources to devote to defending against a frustrating pirate raid (which nobody even paid for) which isn't going to benefit me at all.

It isn't a question of whether I can handle it or not, it's a game mechanic which should obviously be random if no bets are made, but which confusingly picks the same target again and again for reasons that nobody can really explain.

In my opinion, killing Pirate ships should give you a small cash bonus for killing them (not much but something) making the player think twice about sending them if the player they are facing has a good defense set up, or to give an unlucky player some kind of consulation for getting shafted all game.

Typically, when all players have the same amount of bounty against them (usually its 0, like at the start), the pirates just choose a random target (I'm fairly sure if you kept a tally of how many times you were targeted first, you would find its near the expected probability of you being selected first - so if you started 100 games with 10 players, odds are that you would be the first target around 10 of those times). Sins isn't exempt from the sacred laws of statistics (unless someone proves the system is not random).

However, if two players have the same amount of bounty against them, the Pirates go after the person who was first to reach that bounty level, i.e. if player A got 1k bounty put against them (and made them the highest), then player B soon got 1k bounty put against them, the Pirates would target A when they launch their raid. If both players still have the same bounty against them when deciding the next target (which is immediately after the countdown timer resets), its random.

if pirates give u headache just thank them by visiting their base wit ur main fleet

yeah not to mention whacking a pirate base adds up to minimum 300k hull dmg in post game statistics