From: Boulder, CO
Well... for a period of a couple years I thought the pirates might take me out. Half my planets had Hidden Pirate Bases on them (along with the endless obligatory ground battles), my colonies were getting raided regularly (sometimes successfully), installations getting attacked, freighters AND warships getting boarded and captured- by pirates, pirate fleets whacking my military fleets, and countless smuggling attacks... all happening in rapid succession, truly desperate times. Finally, improvements in technology aided the fleet; growing populations made it more difficult for the pirates to challenge me on my colonies, improved ground and space-based colony defenses cut down on the raids, and who knows what else contributed to things quieting down- a lot.
I've not had so much fun in a long time in a game!