I had a pretty high bounty on me, and I ended up with a HUGE pirate fleet around one planet. At least 60 ships. I had a bunch of my own ships around that planet, plus it was fully fortified with about 8 hangar's. I was holding my own, it was going to be rough but I knew I could take them. This was a Terran class planet, fully upgraded in population/planet health. Suddenly all the pillagers broke from combat and went for the planet. There were about 15 of them. Once I realised what was happening I sent all my bomber squadrons after them and broke some of the main fleet to attack them, but it was too late. They wiped the planet out in under two minutes.
I would have had no problem if the pillagers had kept fighting my fleet, and I don't mind pirates being able to destroy a planet, but that fast when I still had a large fleet defending? It happened again to an asteroid, they wiped it out in under 30 seconds or so. The pirates damage to planets (and only that) needs to be nerfed big time. They can do damage, just not so much so fast.