Ok, I really love this game (precursor to the "but this ticks me off" part
), and this is my 4th Huge game.
But this is the first time this has occured.
I created the game with normal settings, 8 players, Pirates, and 2 out of the 8 AIs were hard, and the other 6 were on normal.
The solar system I started out in ends up containing 4 AIs, one of which is a hard AI. The solar system had about 28 planets total.
About half way through, (before my demise) and 20 minutes in, the Hard AI decides to attack one of my planets - no big deal, iv got the skill and the ships to combat their assault.
Then I notice that one of the computers that were boxed in by me, who are near my planet that is under attack, joined the fight against me. 3 minutes later, the other 2 AIs join in the assault against me.
Now before this I attempted to boost my standing with the other factions, however I cant do all of them at once because I dont have the fleets to appease all of their missions and defend my bases at once. So even if I had chose to make friends with 2 of them, it would have been a long stretch to defeat both computers fleets on two seperate fronts to gain access to the mission objectives, and defend my position from the other two AI.
But! After watching the recording, the AIs dont need to do the same thing I have to do to make friends ; I watched the Hard AI diplomacy screen before my planet was attacked, and boom - within about 3 minutes all the players in the solar system decided they wanted to form ceace fire/fleet & planet vision/cooperation in attacks.
Their percentage of trust with eachother was at 0%, but that wasnt as alarming as : "Hey, wanna be friends?" "Sure thing! Here is what im going to do next, join me for this panty-raid!" - where as when they talk to me "Hey there, wanna call a ceace fire?" "Nah, im good, im not the kinda guy to do something like that for no good reason. You seem like a nice guy though."
I reviewed my replay, nothing I could have done could have prevented the attack. I built as many ships as I could, almost as fast as the Hard AI, but since they decided to gang up on me there was no way to stop it.
Is it a bit odd that iv got to jump through hoops to make someone happy, but total strangers can just decide to be friends on a whim? It obviously lead to my empires death, my first defeat in months, but there was no way to avoid it, and im a bit miffed that the computer doesnt have to play by the same rules I do. Id like to see the computer play by the same rules, or be on some sort of equal footing, to make this a more believable situation, or at least a situation that could be combatted.
Was the only way to win not to play? What is the purpose of starting a game where the outcome must be defeat? What were the odds that all of them would decide to become friends at the same time? I wouldnt mind losing so much, if there was something to learn from it, but in this case the lesson seems to be "dont play against a stacked deck" - no surprise there 
I like my single player and multi player games, but id like to see this issue fixed at some point. I think what ever causes it makes this scenario unrealistic, and obviously no fun at all.
Thanks for your time!