I know that this couldn't happen in single player (read the subtitle).
Lets say two players have been at war for...awhile, with one eventually pushing the other way back. The one that has been pushed back then comes under attack by pirates or another faction and can't handle a two front war. So the second guy asks the first guy for an alliance, and the first agrees as long as he gets some reparations. The second guy cannot meet the first guy's demands and asks if he could give something else to appease the first guy. The first guy thinks that if he wants to protect the second guy, he'd need a base in the second guy's territory. So the first guy picks out a planet held by the second guy. The second guy pulls out all of his ships and scuttles all the buildings, and the planet is evacuated (or the population stays there) and the second guy gets control.
So, basically, I'm wondering if in the online beta, not only can you give resources to help allies or as reparations, I'm wondering if you can give whole planets (because right now the only way for a planet to change owners is if it gets bombed, and allies can't bomb each other's planets).
Random question because I didn't feel like making it another topic: can you pay off your own bounty now (and I just didn't realize it) or can you pay it off in a furture patch/ beta?