[dmm]

The unbelievable thing is that billions of rioting people would voluntarily board transport ships!!! The game should not allow that. You should not be able to move around populations until they get to a certain happiness level. Likewise, you shouldn't be able to "cure" a plague by evacuating the entire population. (And speaking of plague, it should spread from planet to planet if it isn't cured or the planet quarantined. [Quarantine would have the same effect as besieged.])