everyone, for the sake of knowledge!!!
tell me two things:
1) how much of an issue are the pirates (be as descriptive as possible)
2) what difficulty is the AI you play with/how many AI are you playing with?
I assume that theres a correlation. I play with 4 other AI all on hard, and the pirates are pushovers. they will attack in small groups at certain planets, but more often than not a few reinforcements from a local gravity well and the already present planetary defenses will more than squash them with ease.