“Depends on what the aliens thought we were guilty OF, really. Why are we on trial? Because we kill each other? Irrelevant your honor, since your alien fleet is here to wipe out humanity. You aliens kill other species. Is it the ideological reasons we kill each other? There are 190 nations on this planet, with varying ideologies that constantly change and shift. One of them is bound to match your ideological views if you look closely enough (and in some nations, there is no ‘core ideology’, but a bizarre mishmash of belief, which means that even folks in countries you don’t like will have ideologies you approve of).

Is it resources you need? We have water here, but it’s dirty….Try the Kuiper belt, or Saturn’s rings, or the comets, for cleaner water. So, for whatever galactic law were have supposedly broken, whatever moral code we are in violation of, I’d find the loophole, the exemption, the excuse to get them to back off. If all else fails, if humans truly WERE reprehensible and irredeemable, I’d argue that the court is wasting resources because we are very likely to wipe ourselves out in a few hundred years anyway, so why bother expending effort to kill something that’s already dead?”