Yes, mid game, about 1:30 in, 3 games in a row now. Take my entire fleet (probably 3 caps and 30-50 frigates) and simply stage an all out assault, I've only had to retreat once because of an AI attack while I was fighting the pirates. I usually lose 2-10 frigates and no caps.

Also did a late game raid on a pirate base in one of my enemy's space after taking it, had 6-9 caps and a full fleet supply (probably 50-100 frigates, I didn't build them, got them from the Dark Fleet ability), that was much harder.

The later you attack the pirates the more stuff they have but they always have a pretty powerful fleet. It's a balancing act of getting a large fleet quickly and wiping them out.

(I play on normal by the way, in case that affects the pirate difficulty. I also outbid until I've wiped them out of my system).

Yes have always taken out pirate bases with little trouble. Just build a nice big fleet with some capitals and lots of frigates and you will be fine. Also make sure your fleet doesn't do something stupid like run into the gauss cannon ring. Get some long-range missile boats and take out the gauss cannons that way, use your caps to take out the pirate ships.

Also, the pirates have lots of low-tech frigates, so get tons of fighter squadrons (talking about 25+ squads here) and you can own them really easily.

I just send all ships in there, no capital even. And do something else. after its dead i use my shortcut key to turn on autocast on all phase gates, and instantly replace the losses

eh I just kill em at the end of a game if I still feel like playing, 1 last challenge for ya.

I think that it increases the number of ships that will attack you when the timer hits zero.

I got the AI down to one planet, so I used one of my fleets to hold them there and destroy their infrastructure. While this was happening I phased my 2 larger fleets straight to the Pirates Base and they got there with-in about 5 seconds of each other and after a fairly long battle I came out on top. Only just mind you, from the screenshot below you can see all that was left of the 2 fleets (combined total of 3 Capital ships and a 60 strong mix of other ships). My 3 capitals made it out ok, but the other surviving ones are a little worse off.



So if you want to give your fleets something to chew on then hitting the Pirates' base is well worth it. Including some great moments to make some screenshots.

I had a game recently where I got a ceasefire and trade alliance with both neighbouring AI players. I don't think they were at peace with each other, because they each gave me missions to attack the other one... but they both simultaneously took big fleets to the pirate base and wiped out the pirates.

I threw my ships in to help, but I think probably either AI could have cleared the pirates on their own - they were both big fleets. I was hoping they'd destroy each other afterwards, but while there were still a lot of ships left on both sides one AI declared war on me and I attacked their homeworld in response so they pulled the pirate-killer fleet back (rather too late) to try to relieve the siege. The game was unfinished though, aborted by some weirdness when Sins triggered a firewall pop-up and then exited. Especially weird a good couple of hours into a non-network single-player game.